Boesche, Roger (2003). The First Great Political Realist: Kautilya and His Arthashastra (на језику: енглески). Lexington Books. стр. 62 A superintendent must issue sealed passes before one could enter or leave the countryside(A.2.34.2,181) a practice that might constitute the first passbooks and passports in world history. ISBN9780739106075.
George William Lemon (1783). English etymology; or, A derivative dictionary of the English language. стр. 397. said that passport may signify either a permission to pass through a portus or gate, but noted that an earlier work had contained information that a traveling warrant, a permission or license to pass through the whole dominions of any prince, was originally called a pass par teut.
James Donald (1867). Chamber's etymological dictionary of the English language. W. and R. Chambers. стр. 366. „passport, pass'pōrt, n. orig. permission to pass out of port or through the gates; a written warrant granting permission to travel.”
