Cita APA (7th ed.)

Heer, F. (1961). The medieval world Europa 1100 - 1350. A mentor Book.

Cita Chicago (17th ed.)

Heer, Friedrich. The Medieval World Europa 1100 - 1350. New York: A mentor Book, 1961.

Cita MLA (9th ed.)

Heer, Friedrich. The Medieval World Europa 1100 - 1350. A mentor Book, 1961.