I am using TexPad as editor and I do the latex, bibtex, latex, latex compilation. The weird thing is that I have two citations that show up and two that come as question marks, I am really puzzled about what the problem is and would appreciate help very much.
This is my tex code:
\documentclass{article}
\usepackage{plain}
\begin{document}
xx\cite{Yu}
\cite{doiX}
\cite{labinger}
\cite{ab}
\bibliography{references}
\bibliographystyle{plain}
\end{document}
and my .bib file:
@article{doiX,
author = "He Hao and Ling-Yan Chen and Wai-Yeung Wong and
Wing-Hong Chan and Albert W. M. Lee",
title = "Practical Synthetic Approach to Chiral Sulfonimides (CSIs)
Brnsted Acids for Organocatalysis",
}
@book{Yu,
series = {Topics in current chemistry},
volume = {292},
publisher = {Springer},
isbn = {978-3-642-12355-9},
year = {2010},
title = {C-H Activation},
language = {eng},
address = {Heidelberg},
author = {Yu, Jin-Quan and Ackermann, xL},
keywords = {ORGANISCHE SYNTHESE (CHEMIE): 547.057{,
}
@article{labinger,
title = {Understanding and exploiting C-H bond activation},
author = {hallo},
journal= {Nature},
volume = {417},
number = {6888},
pages = {507},
year = {2002},
publisher={Nature Publishing Group}
}
@article{ab,
author = "He Haond Ling-Yan Chen and Wai-Yeung Wong and
Wing-Hong Chan and Albert W. M. Lee",
title = "Practical Synthetic Approach to Chiral Sulfonimides
(CSIs) Brnsted Acids for Organocatalysis",
}
and this is what the output looks like:
The error in the log says:
LaTeX Warning: Citation `ab' on page 1 undefined on input line 8.
(./BiBTexTest.bbl) [1{/usr/local/texlive/2017/texmf-var/fonts/map/pdftex/updmap
/pdftex.map}] (./BiBTexTest.aux)
LaTeX Warning: There were undefined references.

plainpackage? AFAICT, it's meant to be used for users who wish to enter plain-TeX commands in LaTeX document. Is that the case in your document? – Mico Jul 01 '18 at 07:01