Beck, Raymond W., author
Burgess, 1977, 1977
Buku Teks
Eiser, Arthur L., author
Burgess , 1970
Buku Teks
Mader, Sylvia S., author
McGraw-Hill , 1998
Buku Teks
Case, James F., author
Macmillan, 1979
Buku Teks
Ritchie, Donald D., author
Addison-Wesley, 1983
Buku Teks