APA (7th ed.) Citation

Evans, I. O. (1966). The observer's book of flags: By I.O. Evans (Rev. ed.). Warne.

Chicago Style (17th ed.) Citation

Evans, Idrisyn Oliver. The Observer's Book of Flags: By I.O. Evans. Rev. ed. London [u.a.]: Warne, 1966.

MLA (8th ed.) Citation

Evans, Idrisyn Oliver. The Observer's Book of Flags: By I.O. Evans. Rev. ed. Warne, 1966.