Ranny, Austin
Prentince-Hall, 1987
Buku Teks
Coyle, David Cushman, 1887-1969
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
edited by Allen F. Davis and Harold D. Woodman
D.C. Heath, 1984
Buku Teks