Cita APA (7th ed.)
Pirenne, H., & Halsey, F. D. (1925). Medieval cities: Their origins and the revival of trade. Doubleday.
Cita Chicago (17th ed.)
Pirenne, Henri, i Frank D. Halsey. Medieval Cities: Their Origins and the Revival of Trade. New York: Doubleday, 1925.
Cita MLA (9th ed.)
Pirenne, Henri, i Frank D. Halsey. Medieval Cities: Their Origins and the Revival of Trade. Doubleday, 1925.
Atenció: Aquestes cites poden no estar 100% correctes.