Jahr → 1921-1930

• Foreign affairs New York, NY : Council on Foreign Relations, 1.1922/23 -, 1922-

• Modern Egypt : a list of references to material in the New York Public Library New York : The New York Public Library, 1929

• Ibn Khaldun : historian, sociologist and philosopher Schmidt, Nathaniel ; Ibn-Ḫaldūn, ʿAbd-ar-Raḥmān Ibn-Muḥammad New York : Columbia University Press, 1930