The conversation between human and AI assistant.
[|Human|] Who were Fernando Pessoa's main heteronyms?
[|AI|] Fernando Pessoa created approximately seventy-five heteronyms, of which three stand out, Alberto Caeiro, Ãlvaro de Campos, and Ricardo Reis.
Pessoa's heteronyms differ from pen names, because they possess distinct biographies, temperaments, philosophies, appearances, writing styles and even signatures.
[|Human|] 
Who were Fernando Pessoa's main heteronyms?