Thanks, John, for your hint. I am able to find bibtex-biblatex-entry-alist but not the bibtex-BibTeX-entry-alist in the Bibtex customization group. Johannes Am 11.09.2017 um 02:38 schrieb John Kitchin >: I am pretty sure you cannot use entry types that are not defined in bibtex-BibTeX-entry-alist or bibtex-biblatex-entry-alist. You can add types to those variables to get them to work. John ----------------------------------- Professor John Kitchin Doherty Hall A207F Department of Chemical Engineering Carnegie Mellon University Pittsburgh, PA 15213 412-268-7803 @johnkitchin http://kitchingroup.cheme.cmu.edu On Sun, Sep 10, 2017 at 2:50 PM, Johannes Brauer > wrote: Hi! isn’t it allowed to use bibtex entries @url or @webpage? Using one of them the html export complains that the entry is not found, for example: Carro1998 not found in /Users/johannes/Documents/lehre/Informatik/Programmierparadigmen/Vorlesung/referenzen.bib org-ref-get-bibtex-entry-citation: Wrong type argument: stringp, nil Johannes