APA (7th ed.) Citation

Juan XXI, P. (1972). Tractatus: Called afterwards Summule Logicales. Van Gorcum.

Chicago Style (17th ed.) Citation

Juan XXI, Papa. Tractatus: Called Afterwards Summule Logicales. Assen: Van Gorcum, 1972.

MLA (9th ed.) Citation

Juan XXI, Papa. Tractatus: Called Afterwards Summule Logicales. Van Gorcum, 1972.