Olumoroti, Olumuyiwa John, author
Elsevier, 2005
Buku Teks
edited by W. Arthur Cullman and Harry R. Knudson
Prentice-Hall, 1972
Buku Teks
Straus, George, author
Prentice-Hall, 1967
Buku Teks
Kelley, Pearce Clement, author
Prentice-Hall, 1952
Buku Teks
Cotlar, Morton
Prentice-Hall, 1974
Buku Teks