From Phillip Helbig (undress to reply@21:1/5 to All on Sun May 16 14:10:17 2021
I'm trying to figure out how to use the spphys.bst for Foundations of
Physics together with natbib, in particular its \citet command. There
is a natbib option to the required svjour3 class, but I get better
results by leaving it out and loading natbib explicitly, at least if I
want to use \citet.
I don't want to change the .tex source to avoid \citet. (Note that
\citep works OK).
I can hack it like this:
o first process normally, including BibTeX
o use unsrtnat.bst to produce a .bbl file in the proper format
o process using the .bbl generated in the previous step
o replace that .bbl with the original .bbl
It produces some errors along the way, but seems to basically work.