With ox-bibtex.el [[cite:(page n)one-reference-paper-year]] will export as
\cite[page n]{one-reference-paper-year}
I am sorry Eric but [[cite:(page n)one-reference-paper-year]] breaks the bibliography reference for me with ox-bibtex.el ... it is too bad because it was a convenient solution to get \cite[page n]{one-reference-paper-year} .