Russell Sage Publication, 2001
Buku Teks
Ranny, Austin
Prentince-Hall, 1987
Buku Teks
Coyle, David Cushman, 1887-1969, author
Rutgers UNiversity Press, 1957
Buku Teks
Cuber, John F
Henry Holt And Company, 1951
Buku Teks
edited by Allen F. Davis and Harold D. Woodman
D.C. Health, 1984
Buku Teks