Marslan, Douglas
Holt, Rinehart and Winston, 1964
Buku Teks
Bailey, Paul C.
International Textbook Company, 1969
Buku Teks
Mader, Sylvia S.
McGraw-Hill , 1998
Buku Teks
Case, James F.
Macmillan, 1979
Buku Teks
Ritchie, Donald D.
Addison-Wesley, 1983
Buku Teks