German Umlauts in BibTeX

Question

I have the following BibTeX source

@INPROCEEDINGS{Lincke2008,
  author = {Rüdiger Lincke and Jonas Lundberg and Welf Löwe},
  title = {Comparing software metrics tools.},
  booktitle = {ISSTA},
  year = {2008},
  editor = {Barbara G. Ryder and Andreas Zeller},
  pages = {131-142},
  publisher = {ACM},
  added-at = {2008-08-04T00:00:00.000+0200},
  biburl = {http://www.bibsonomy.org/bibtex/2c28c4fff6d811b643940228935a20e28/dblp},
  crossref = {conf/issta/2008},
  date = {2008-08-04},
  description = {dblp},
  ee = {http://doi.acm.org/10.1145/1390630.1390648},
  interhash = {69e9d6ded70716bc2bb9319abfbb015f},
  intrahash = {c28c4fff6d811b643940228935a20e28},
  isbn = {978-1-60558-050-0},
  keywords = {dblp},
  url = {http://dblp.uni-trier.de/db/conf/issta/issta2008.html#LinckeLL08}
}

I'm managing my BibTeX items with JabRef. Now if I want to cite this item and while generating the PDF i get the following error:

! Package inputenc Error: Keyboard character used is undefined
(inputenc)                in inputencoding `utf8x'.

See the inputenc package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.29 R�
       diger Lincke, Jonas Lundberg, and Welf L�we.

I think the problem is the character ö. How can I avoid that? I also had similar problem with the character é.

@StephanKolassa -- Although that question does answer the question for pdflatex, if one uses the utf8 coding and xelatex or lualatex, the single Unicode accented character should work. The cited question needs an updated, properly qualified answer. — barbara beeton, May 05 '23 at 14:25

score 13 · Answer 1 · answered Feb 05 '11 at 00:27

13

If you use utf8(x) in your tex file, ensure that your BibTeX source file is utf8 encoded as well.

You might use

an editor supporting different encodings, opening (in latin1 or accordingly) and save it in utf8 encoding
recode
iconv

If you don't use utf8(x) in your tex file, load inputenc with the respective option. Or convert the tex file to the same encoding as the BibTeX source and adjust the inputenc option accordingly.

To sum up, the encoding of all involved files should be the same and match the inputenc option.

answered Feb 05 '11 at 00:27

Stefan Kottwitz

231,401

Thanks a lot, encoding the database in UTF-8 solved the problem! – RoflcoptrException Feb 05 '11 at 00:30
2

But BibTeX doesn't really do UTF8... – Martin Schröder Jan 26 '12 at 22:14
1

@MartinSchröder, what are the limitations? The fact that utf8 in a .bib file only works with a utf8-input-encoded TeX-document? Or are there other pitfalls with utf8 and BibTeX? – maxschlepzig Mar 28 '12 at 12:47
1

@maxschlepzig: How would a 7-bit program (which BibTeX is) sort UTF-8 strings? How would it generate labels etc.? – Martin Schröder Mar 28 '12 at 15:33
@MartinSchröder, Sorting of UTF-8 strings as arrays of unsigned bytes will produce the same results as sorting them based on Unicode code points. ;) - but fair enough, using non-numeric labels would be a problem. – maxschlepzig Mar 28 '12 at 17:46

score 11 · Accepted Answer · edited Jan 26 '12 at 20:48

11

Instead of actually entering the ö and é characters in your source, type \"{o} and \'{e}.

Or rather: Yrjö Engeström as {Yrj{\"o} Engestr{\"o}m}.

edited Jan 26 '12 at 20:48

N.N.

36,163

answered Feb 05 '11 at 00:18

Andrew

1,514

in the BibTeX source or where? – RoflcoptrException Feb 05 '11 at 00:18
1

@Roflcoptr - Anywhere they appear in your source. Edited for clarity. – Andrew Feb 05 '11 at 00:19
Then i get this error: ! Package inputenc Error: Keyboard character used is undefined (inputenc) in inputencoding `utf8x'.
See the inputenc package documentation for explanation. Type H for immediate help. ...

l.29 R� diger Lincke, Jonas Lundberg, and Welf L"{o}we. ?
– RoflcoptrException Feb 05 '11 at 00:21
1

@Roflcoptr - Make sure your source files are encoded in ANSI instead of UTF-8. – Andrew Feb 05 '11 at 00:22
@Andrew S. Arnold Thanks a lot, encoding the database in UTF-8 solved the problem – RoflcoptrException Feb 05 '11 at 00:30
Ah, I had it backwards. Well, as long as you fixed it, that's the important thing! – Andrew Feb 05 '11 at 00:31

German Umlauts in BibTeX

2 Answers2