I'm writing a paper about Fernando Pessoa and his heteronyms and want to use a quote from Pessoa as written on the Wikipedia article: "the theatre of being" or "drama in people."
Wikipedia does not cite the source of these quotes, and I assume from the context of the sentence they're in that it is a direct quote from Pessoa's work, but I can't read through everything he's written to try to find it. Is it possible to cite quote as "source unknown" or something similar? I'm fairly certain I've heard the quote before from a professor (she also did not know where to look for the quote's source) so I don't believe it's fake.