[texhax] problems with placing references

[Geert Scholma]

hi tug,

I use Texshop 2 (2.04) with bibdesk 1.2.6 (v302). I have only 1 bib
file, which is iesthesis.bib and it is in the same folder as the tex
file itself. When I try to put three references in my document, only
the middle one (which I inserted some time ago), works.

\cite{TRS}\\
\cite{NGP}\\
\cite{DMS}\\

\bibliographystyle{plain}
\bibliography{iesthesis.bib}

These are the warnings:
LaTeX Warning: Citation `TRS' on page 3 undefined on input line 30.
LaTeX Warning: Citation `DMS' on page 3 undefined on input line 32.

I triple checked the names of the citations, and I cannot think of
anything more that I do wrong. Do I have to update the library, or do
something else? Could you please help me through this difficult
first-time-user experience?

Geert