McGraw-Hill, 1956
Buku Teks
Walters, Margan L
N.Y.Holt,Rinehart and winston,ic, 1966
Buku Teks
Holt, Rinehard and Winston, Inc.
Holt, Rinehart and Winston,Inc, 1966
Buku Teks
Holt, Rinehart and Winston, 1966
Buku Referensi
Jones, Leo
Cambridge University Press, 1989
Buku Teks