🚀 go-pugleaf

When trying to use the lines ...
	\bibliographystyle{ieeetr}
	\bibliography{big}
under the letter.sty I noted that my subsequent 
	bibtex filename
command resulted in an error...no filename.aux had been created by
	latex filename
So I tried doing it by hand and replaced the \bibliography commands above
with
	\begin{thebibliography}{3}
	stuff...
	\end{thebibliography}
This also failed to work giving me an undefined environment error.

Is there a fix to letter.sty that I can use to allow me to put in a
bibliography?  Or shall I go on to more detailed hand formating?

Tnx,
mike