_:vb7555970 "2020, Emmet Sweeney, The Theban Empire, volume 3, page 176:"@en . _:vb7555968 "(intransitive, informal) To be knowledgeable about and competent at a particular subject or task."@en . _:vb7555969 "Joe really knows his stuff when it comes to baseball."@en . . . _:vb7555970 . . "1" . _:vb7555969 . . . . _:vb7555970 "The field of knowledge in which Hori claimed to be an authority was Palestinology. The contents of the missive show that Hori certainly knew his stuff."@en . _:vb7555968 . . .