McGraw-Hill, 1956
Buku Teks
Taylor, Grant
Saxon Press, 1956
Buku Teks
Hadfield, Jill
International Thomson Publishing Company, 1995
Buku Teks
Jones, Leo
Cambridge University Press, 1989
Buku Teks
Walters, Margan L
N.Y.Holt,Rinehart and winston,ic, 1966
Buku Teks