I'm pretty new to TeX so please forgive me if this requires just a simple solution. I'm writing a thesis that uses almost 100% English characters exclusively, except for a case where an author I cite has a Turkish name, starting with the letter Ş. I'm using natbib and bibtex, with the bibliographystyle = chicago.

I've gotten everything to work just as I want it, except in the bibliography the Turkish author's entry is not in alphabetical order, instead appearing between the letters C and E.

  • Coleman, R. G. and X. Wang (1995). Overview of the Geology and Tectonics of UHPM. In R. G. Coleman and X. Wang (Eds.), Ultrahigh Pressure Metamorphism (1 ed.)., Chapter 1, pp. 1–32. Cambridge: Cambridge University Press.
  • Şengor, A. M. C. and B. A. Natal’in (1996). Paleotectonics of Asia: fragments of a synthesis. In A. Yin and M. Harrison (Eds.), The Tectonic Evolution of Asia (1 ed.)., Chapter 21, pp. 486–640. Cambridge: Cambridge University Press.
  • Ernst, W. G. and J. G. Liou (2008, November). High- and ultrahigh-pressure metamorphism: Past results and future prospects. American Mineralogist 93(11-12), 1771–1786.

I've read through everything I can think of at this point but I can't figure out why it's in that order and can't figure out how I can somehow customize it so that it shows up with the S authors. I know that there are suggestions to use biblatex and biber, but I am novice enough that I don't know if I can figure out how to get that to work (getting to this point where I am was difficult enough...). I even tried using the key field in the .bib file, but that was not successful. Here is the .bib entry:

abstract = {},
address = {Cambridge},
author = {\c{S}eng\"{o}r, Ali Mehmet Cel\^{a}l and Natal'in, Boris A.},
booktitle = {The Tectonic Evolution of Asia},
chapter = {21},
edition = {1},
editor = {Yin, An and Harrison, Mark},
keywords = {Asia,cratons},
mendeley-tags = {Asia,cratons},
pages = {486--640},
publisher = {Cambridge University Press},
title = {{Paleotectonics of Asia: fragments of a synthesis}},
year = {1996}}

Any ideas for what I should try? I'm sure there is a solution but I'm not familiar enough with the system to know where it may lie. Much appreciated!

  • 1
    Just a short comment: Exactly because you're a novice you shouldn't bother with traditional bibtex and have instead a look at biblatex/biber. There's no reason to use outdated software when better alternatives already exist. Don't create a legacy problem for yourself if you don't have to. biber will deal with all Unicode characters without any problems.
    – Simifilm
    Dec 31, 2011 at 9:41
  • 1
    I installed TeXShop to start with and try out this language - and I couldn't figure out how to use biblatex and biber. I hope to at some point though. Dec 31, 2011 at 10:43

2 Answers 2


All special characters need to be grouped separately. As such, use

author = {{\c{S}}eng{\"{o}}r, Ali Mehmet Cel{\^{a}}l and Natal'in, Boris A.},

The reason for the misplaced sorting is because the sorting is probably based on cSengor (stripping all the "special stuff").

The following is taken verbatim from BibTeX Tips and FAQ (p 6) - consider reading about half way down:

Q5: I am confused about the difference between special characters and the use of braces to protect text from case changes. Also, when should I “shield” things with braces?

The rules that govern all this are simple, but confusing. BibTeX considers everything within a {\ .. } construct at brace level 0 (and only brace level 0), that is the top level of bracing of the field (which is not affected by whether quotes or braces are used to delimit the entire field), to be a “special character” and will treat is though the entire construct is a single character. Within special characters, control sequences (LaTeX commands) will be preserved as is, but all other text may be case changed or otherwise processed as needed. Furthermore, within special characters, additional levels of braces do not increment the brace level. On the other hand, { .. } constructs at brace level 0 (the key here is that a \ does not immediately follow the opening brace — if so, it would make it a special character) do increment the brace level as well as do nested braces within them. All text and control sequences at brace level 1 or higher is protected from case changes or other processing.
It is perhaps easier to understand from an example. Consider:

title = "L0 {\relax S0 {S0 {S0}}} L0 {L1 {\relax L2 {L3}} L1} \LaTeX\ L0"

where Lx indicates brace level x and Sx indicates a (part of a) special character at brace level x. Again, nothing would change here if braces had been used to delimit the entire field instead of quotes. The three S0’s are all considered to be part of the same special character because they are all within a {\ .. } construct at brace level 0. Text at S0 may be case changed, but the \relax as well as other control sequences in S0 will not be changed. Note that the additional nested braces within the special character do not increment the brace level. Thus, there is no such thing as S1 or higher. The first L1 is at brace level 1 because it is a { .. } (and not a special character). Note that in this case, additional levels of braces do increment the brace level counter. Furthermore, the second {\relax .. is not treated as a special character because it occurs at brace level 1. All characters and control sequences at L1 and higher will be protected from case changes. Note that in this example the control sequence \LaTeX is subject to case changes. Thus, if the bibstyle set the title to lowercase, the resultant \latex command would likely generate an error.
With all this in mind, we can look at some practical examples. Consider:

title = "Secrets of {NASA}"

NASA needs to be enclosed in braces because it is an acronym that must remain in uppercase. Likewise, we usually need to protect math from case changes:

title = "The {$A_\beta$} Protocol"

Simple argumentless LaTeX commands are also easily protected:

title = "The {\LaTeX} Book"

However, note that in this case, \LaTeX will be treated as a special character and so the text “LaTeX” will not be considered when sorting. Thus, in cases where the name of the LaTeX command is identical to the text it represents, it may be better to use an extra set of braces so that the letters that make up the command will be taken into consideration when sorting:

title = "The {{\LaTeX}} Book"

Another application of brace shielding is with titles in languages (such as German) in which title capitalization must be preserved with some words (such as nouns and names):

title = "{M}essung von {S}t{\"o}rfeldern an {A}nlagen
         und {L}eitungen der {T}elekommunikation im
         {F}requenzbereich 9 {kHz} bis 3 {GHz}",

Note that {\"o} is treated as a special character and the “o” is not protected against case changes. However, the first letter of the nouns are protected because they are at brace level 1.
Things get a bit more complicated when a LaTeX command has an argument. The correct approach depends on whether the argument needs to be protected from case changes. Consider:

note = "Volume~2 is listed under Knuth \cite{TEX:book}"

If the bibstyle changes the note field to lowercase, we will get:

volume~2 is listed under knuth \cite{TEX:book}

so we will likely want to enclose first letter of Knuth’s last name in braces. Furthermore, if we had an unusual bibstyle that rendered the note field in uppercase, we would get:


which would result in an error when the nonexistent \CITE is executed. We might be tempted to try something like this:

note = "Volume~2 is listed under Knuth {\cite}{TEX:book}"

but this won’t work because the extra braces around the \cite command will prevent it from seeing its argument:


Instead, we might try something like this:

note = "Volume~2 is listed under {K}nuth {\cite{TEX:book}}"

However, this is not safe either because the cite key “TEX:book” is now considered to be part of a special character and so it may be case changed (just like the second S0 in the example before)! Therefore, we need to employ an additional set of braces to get the \cite command and its argument to brace level(s) greater than zero:

note = "Volume~2 is listed under {K}nuth {{\cite{TEX:book}}}"

so as to ensure everything will work regardless of what the bibstyle does to the note field.
It is usually a good idea to let the .bst file convert/format the fields as it sees fit — so don’t force things with extra braces unless you have to. Future versions of BibTeX may be more intelligent with respect to case changing and thus may require fewer “manual interventions” with braces. [...]

  • 3
    I'm astounded, on the eve of 2012, that anyone can call "Ş" a "special character". Even if we don't yet have full support for sorting in national collating orders, I think it would be healthier to call it "Unsupported National", rather than "Special." Dec 31, 2011 at 9:14
  • @Brent.Longborough - "Special character" is a set term in BibTeX. It means, for all intents and purposes, "any alphabetic character not included in the 7-bit ASCII table". No more, no less. (Of course, the fact that BibTeX still expects input to be 7-bit ASCII is, shall we say, troublesome...)
    – Mico
    Feb 25, 2018 at 19:35

The author field of the bib entry in your example code should look like this:

author = {{\c S}eng{\"o}r, Ali Mehmet Cel{\^a}l and Natal'in, Boris A.},

Compared with the form given in your example, the accented characters are "enclosed" in curly braces. With this change, the entry will be sorted under "Sengor".

  • I believe that Ş is not actually an "accented character", but is considered another character of the alphabet in its own right. Perhaps one of our Turkish friends could confirm or deny that. Dec 31, 2011 at 9:17
  • 1
    It is, but in a document in English one would probably collate it together with "S".
    – egreg
    Dec 31, 2011 at 10:00
  • @Brent.Longborough Indeed, it is included as a separate letter (U+015E). It is between S and T letter in the alphabetical order.
    – percusse
    Dec 31, 2011 at 10:10
  • 2
    @egreg Yes, I remember the difficulty I had once, finding a word starting with "Ll" in my Spanish dictionary. Maybe the collating order doesn't depend only on the (sub)language, but also on the audience? Dec 31, 2011 at 10:55
  • 1
    @Brent.Longborough I'd say yes; while a paper by Ångström would be at the end of a list in a Swedish document, it should be among other "A" entries in an English (or Italian) one.
    – egreg
    Dec 31, 2011 at 10:57

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