Cita APA (7a ed.)

Spuler, B. (1977). Rulers and governments of the world. Bowker.

Cita Chicago Style (17a ed.)

Spuler, Bertold. Rulers and Governments of the World. London [etc.]: Bowker, 1977.

Cita MLA (9a ed.)

Spuler, Bertold. Rulers and Governments of the World. Bowker, 1977.