# Biblatex cite 2 different sources for one paper as [Xa] and [Xb]

I'm using biblatex with numeric style. I think about referring this both sources

This shall be a MWE

\documentclass{scrartcl}
\usepackage[backend=biber,%
bibencoding=ascii,%
style=numeric,%
natbib=true,%                                       Lädt das Kompatibilitätsmodul, welches Pseudonyme für die Befehle der Literaturverweisregeln des natbib-Pakets zur Verfügung stellt.
maxbibnames=3,%                                 Es werden maximal 5 Namen in der Bibliographie ausgegeben
sorting=nyt,%                                       Name, year, title
giveninits=true,%                               Vornamen werden abgekürzt
uniquename=init,%                           Einzigartige Namen werden abgekürzt
isbn=false,%                                        Isbn wird nicht ausgegeben
doi=false,%                                         doi wird nicht ausgegeben
clearlang=false,%                               weiß ich nicht
maxcitenames=3,%                                    in Zitationen erscheinen höchstens zwei Autoren
urldate=comp,%
defernumbers=true%
]{biblatex}
\RequirePackage{filecontents}
\begin{filecontents*}{\jobname-bib.bib}

@misc{Kim_Barbulescu-2016,
author = {Taechan Kim and Razvan Barbulescu},
title = {Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case},
howpublished = {Cryptology ePrint Archive, Report 2015/1027},
year = {2016},
url = {http://eprint.iacr.org/2015/1027},
urldate = {2017-03-20},
keywords = {paper}
}
@Inbook{Kim_Barbulescu-2016b,
author="Kim, Taechan and Barbulescu, Razvan",
editor="Robshaw, Matthew and Katz, Jonathan",
title="Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case",
bookTitle="Advances in Cryptology -- CRYPTO 2016: 36th Annual International Cryptology Conference",
year="2016",
publisher="Springer Berlin Heidelberg",
pages="543--571",
isbn="978-3-662-53018-4",
doi="10.1007/978-3-662-53018-4_20",
url="http://dx.doi.org/10.1007/978-3-662-53018-4_20",
keywords = "paper"
}
\end{filecontents*}
\bibliography{\jobname-bib}
\begin{document}
\nocite{*}
\end{document}


Since those are both the same releases, I would like to list them as different sources highlighted by [Xa] and [Xb] (where X is a natural number)

My first question: Would you refer to both publications? How can I reach my intention?

• Are you using a numeric-family style? Can you maybe show us a real MWE of the rest of your bibliography setup. An answer will heavily depend on the way you obtain the bibliography. – moewe Mar 20 '17 at 14:40
• But frankly, if they are the exact same paper I would not bother putting both in the bibliography, just cite the one you actually worked with. If they are different, I would prefer for the two two have different labels and not just 'sublabels'. You may want to have a look at the related functionality that biblatex offers. – moewe Mar 20 '17 at 14:42
• @moewe I try to. But I guess I only will refer to the reviewed version. – Shalec Mar 20 '17 at 14:48
• As it's one and the same paper, I would not cite different sources, but add eprint="http://eprint.iacr.org/2015/1027" to the @Inbook entry. – samcarter_is_at_topanswers.xyz Mar 20 '17 at 15:59

If you want both entries to appear in the bibliography, you can use @set

@set{kimburb,
entryset = {Kim_Barbulescu-2016,Kim_Barbulescu-2016b},
}
@online{Kim_Barbulescu-2016,
author       = {Taechan Kim and Razvan Barbulescu},
title        = {Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case},
howpublished = {Cryptology ePrint Archive, Report 2015/1027},
year         = {2016},
url          = {http://eprint.iacr.org/2015/1027},
urldate      = {2017-03-20},
}
@inproceedings{Kim_Barbulescu-2016b,
author    = {Kim, Taechan and Barbulescu, Razvan},
editor    = {Robshaw, Matthew and Katz, Jonathan},
title     = {Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case},
booktitle = {Advances in Cryptology -- CRYPTO 2016: 36th Annual International Cryptology Conference},
year      = {2016},
publisher = {Springer},
pages     = {543--571},
doi       = {10.1007/978-3-662-53018-4_20},
}


This comes very close to what you had in mind if you use the subentry=true option of the numeric styles.

But you could add Kim_Barbulescu-2016 as related entry in Kim_Barbulescu-2016b if you want:

@online{Kim_Barbulescu-2016,
author       = {Taechan Kim and Razvan Barbulescu},
title        = {Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case},
howpublished = {Cryptology ePrint Archive, Report 2015/1027},
year         = {2016},
url          = {http://eprint.iacr.org/2015/1027},
urldate      = {2017-03-20},
}
@inproceedings{Kim_Barbulescu-2016b,
author    = {Kim, Taechan and Barbulescu, Razvan},
editor    = {Robshaw, Matthew and Katz, Jonathan},
title     = {Extended Tower Number Field Sieve: A New Complexity for the Medium Prime Case},
booktitle = {Advances in Cryptology -- CRYPTO 2016: 36th Annual International Cryptology Conference},
year      = {2016},
publisher = {Springer},

• @Shalec Why don't you try it out yourself? \cite{Kim_Barbulescu-2016} will work, but you will have to \nocite{kimburb}/\cite{kimburb} the @set in order for the whole set to appear as in the picture and the citation to show with a/b. – moewe Mar 20 '17 at 15:49