Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

Ross, Martha, e Bertold Spuler. Rulers and Governments of the World. London ; New York: Bowker, 1977.

Citatione MLA (8a ed.)

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