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I am new to LaTeX, and I have encountered an error that I couldn't fix myself.

Error: "Missing \endcsname inserted Три \cite{Бідюк2009}"

Неre is a simple document to recreate an error.

\documentclass[a4paper, 14pt, oneside]{report}

\usepackage[english, russian, ukrainian]{babel}

Один \cite{Congdon2006}

Два \cite{Koch2007}

Три \cite{Бідюк2009}


The bibliography document (source.bib):

% Encoding: UTF8

  title = {Bayesian Statistical Modelling},
  publisher = {John Wiley \& Sons},
  year = {2006},
  author = {Peter Congdon},
  pages = {573},
  edition = {2},
  owner = {Georgii},
  timestamp = {2012.04.01}

  title = {Introduction to Bayesian Statistics},
  publisher = {Berlin: Springer-Verlag},
  year = {2007},
  author = {Karl-Rudolf Koch},
  pages = {249},
  owner = {Georgii},
  timestamp = {2012.04.02}

  author = {Петро Іванович Бідюк},
  title = {Адаптивне прогнозування фінансово-економічних процесів на основі принципів системного аналізу},
  journal = {Наукові вісті НТУУ КПІ},
  year = {2009},
  volume = {5},
  pages = {54--61},
  owner = {Georgii},
  timestamp = {2012.04.01}

Both documents are encoded in UTF-8.

share|improve this question
Depending where your error happens, you should use bibtex8 rather than bibtex to compile your bibliography as bibtex doesn't support UTF-8 encoding. Alternatively, using biber and biblatex could help. – ArTourter Apr 2 '12 at 19:35
@ArTourter thank you for your help, I'll try to do that. The workaround might be changing identifiers to English without changing the contents of the bibitems. I think, I close the question if i find how. – GKalnytskyi Apr 2 '12 at 19:56
up vote 6 down vote accepted

The error is due to the citation key: it's not allowed to use non ASCII characters in them. So change the Бідюк2009 key into Bidjuk2009 or what you prefer.

Use bibtex and not bibtex8, which doesn't support UTF-8, but only 8 bit code pages such as Latin-1. Instead bibtex won't try to interpret any of the character with high bit set.

You should anyway consider switching to biblatex; the problem with citation keys would remain, though.

share|improve this answer
biblatex and xelatex (or lualatex) would presumably solve the bib key issues, as well as all the rest. – wasteofspace Apr 2 '12 at 20:20
@egreg, I think I am using bibtex, and not bibtex8. I don't know because I am using TexStudio and clicked the BibTex button there. Anyway, my mistake was choosing non-ASCII identifiers, so pdfLaTex reported errors. I will look at biblatex later and check if using the combination of XeLaTeX and BibLaTex will help with non-ASCII identifiers. – GKalnytskyi Apr 2 '12 at 20:24

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