Dawson, Robert MacGregor
Vancouver The Copp Clark Publshing Co. 1957,
Buku Teks
Tindal, C. Richard
Nelson Thomson Learning, 2000
Buku Teks
Crawford, Kenneth Grant
University of Toronto Press, 1958
Buku Teks
chapters by Edgar McInnis ... [et al.] ; edited by George W. Brown
University of California Press, 1953
Buku Teks
Smiley, Donald V.
McGraw-Hill Ryerson, 1980
Buku Teks