Conversation so far:
what did bernard have to do with research?
He began his research career with the study of medieval Arab, especially Syrian, history.
what else did he research?
Lewis switched to the study of the Ottoman Empire, while continuing to research Arab history through the Ottoman archives.
what was his biggest accomplishment?
Lewis wrote several influential books.

Question: what were the names of some of his books?
Self-contained rewrite: what were the names of some of Bernard Lewis's books?