Leon, Steven J.
Prentice-Hall, 1996
Buku Teks
White, Myron R.
Allyn and Bacon, inc., 1968
Buku Teks
Sofwah Ahmad
Universitas Indonesia, 2012
UI - Skripsi (Membership)
Hall, James E.
Brooks/Cole, 1971
Buku Teks
Elsevier Science Inc.,,
Majalah, Jurnal, Buletin