Sylla, Edith (2001), "Walter Burley's "Physics" Commentaries and the Mathematics of Alteration", Early Science and Medicine, 6 (3): 149–184, doi:10.1163/157338201x00118, JSTOR4130080
Sylla, Edith (2001), "Walter Burley's "Physics" Commentaries and the Mathematics of Alteration", Early Science and Medicine, 6 (3): 149–184, doi:10.1163/157338201x00118, JSTOR4130080