treatise

n. /ˈtriːtɪs/ C2

专题论文；专著

A formal, detailed piece of writing dealing with a subject systematically.

仙境例句

The old crab wrote a treatise on Laughing and Grief, three hundred pages long.

老螃蟹写了一部关于“笑”和“悲伤”的专论，足足三百页。