Wilde, Lawrence, author
Dartmouth, 1994
Buku Teks
Sweezy, Paul M. (Paul Marlor), 1910-2004, author
McGraw-Hill, 1949
Buku Teks
Collins, James, author
The Bruce Publishing Company, 1954
Buku Teks
edited by Charles K. Warner
Macmillan, 1966
Buku Teks
edited by Charles K. Warner
Macmillan, 1966
Buku Teks