Complex sentence: He studied for a long time many different brazilian aboriginal groups, writing important works about brazilian cultures and racial groups, including his most famous work, "O Povo Brasileiro", a synthesis about the formation of the brazilian society.
Split into simpler sentences: He studied for a long time many different brazilian aboriginal groups, and wrote important works about brazilian cultures and racial groups. His most famous work is called "O Povo Brasileiro", which is a synthesis about the formation of the Brazilian society.