treatise|treatises

这位教授写了一篇关于佛教哲学的论文。

The professor wrote a ___treatise on Buddhist philosophy.

她在图书馆找到了几本关于中世纪医学的专著。

She found several ___treatises on medieval medicine in the library.

这位教授写了一篇关于中世纪哲学的专著。

The professor wrote a ___treatise on medieval philosophy.