Having this bibtex entry in file.bib:

  author = {Newton José Rodrigues da Silva and Jean-Eudes Beuret and Olivier
Mikolasek and Guy Fontenelle and Lionel Dabbadie and Maria Inez Espagnoli Geraldo Martins},
  title = {Modelo Teórico de Análise de Políticas Públicas e Desenvolvimento},
  journal = {Revista de Economia Agrícola},
  year = {2007},
  volume = {54},
  pages = {43-66},
  number = {2},
  month = {jul/dez},
  file = {Silva2007.pdf:Silva2007.pdf:PDF},
  owner = {vinicius},
  school = {Universidade do Estado de São Paulo},
  timestamp = {2012.02.07},
  url = {http://www.cati.sp.gov.br/Cati/_tecnologias/piscicultura/ASP-PISCICULTURA.pdf}

Citing like this on file.tex:





\renewcommand{\-}{\penalty 0}

And compiling it like:

pdflatex file.tex
bibtex file.aux
pdflatex file.tex
pdflatex file.tex

Will prompt on the following error:

[26]) (./tg.bbl [27] [28]
! Undefined control sequence.
<argument> ...ti\-.sp\-.gov\-.br\-/Cati\-/\underl 
l.215 ...logias/piscicultura/ASP-PISCICULTURA.pdf}

Any help is much appreciated.

2 Answers 2


The error is related to the _ in your url field. I'd add \usepackage{url} to the document preamble and replace

url = {http://www.cati.sp.gov.br/Cati/_tecnologias/piscicultura/ASP-PISCICULTURA.pdf}


url = {\url{http://www.cati.sp.gov.br/Cati/_tecnologias/piscicultura/ASP-PISCICULTURA.pdf}}

in your .bib file.

My output:

My output

Hope it helps. :)

Edit: As pointed by Legolas in the comments, some bibliography styles already manage url fields nicely, so the \url trick is not needed.

For abntcite, there's a remark in the manual to load hyperref before abntcite, so the url fields will be correctly displayed. It's a matter of adding


and everything will work as expected, without the need of changing the url field in your .bib file.

My new output:

New output

  • I think this does depend on the bibliography package you use. So, if you were ever to change to, for example, biblatex, you may need to revert these changes. Nevertheless, this is the right answer.
    – Legolas
    Mar 21, 2012 at 8:13
  • @Legolas: Yes, you are absolutely right. :) There are other biblography styles that manage URLs nicely, which IMHO is the way to go. In this particular case I'm afraid the OP needs to stick with abntcite, since it's one of the standards for academic documents in Brazil. Sadly, abntcite seems to not have a URL fallback, so I'd go with \url. :) Mar 21, 2012 at 10:00
  • Thanks @Paulo. I forgot to say that I've seen this solution before, and that I'm using Jabref to manage the bibliography. I would like to keep a "clean" url field so this tool can build links and so. Any other suggestion? Mar 21, 2012 at 10:24
  • @Vinicius: Sure! See my new edit. :) Mar 21, 2012 at 10:36
  • Well, @Paulo. I'm already using hyperref, and still getting the same error. Actually, I just added all my preamble to my question, so maybe you can figure out what's causing the error. I tried different order combinations to load these packages and also removed all packages but abntcite and hyperref in the order you told me. I got nowhere with all this. Any hints would be a great help. Mar 21, 2012 at 22:40

What helped me in a similar case is the protection of fragile makros, by \protect\url{...} which Werner explained here: https://tex.stackexchange.com/a/51052/110394

Hope this helps somebody.

  • Where will you place the \protect in the given issue? Have you tried it? The issue in this question is a problem with _ you can not protect. The solution here is using an bibliographystyle able to handle \urls correctly ...
    – Mensch
    Aug 12, 2019 at 2:28

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