Eble, Kenneth E., author
Jossey-Bass, 1979
Buku Teks
Elizabeth Connor, editor
Routledge, 2008
Buku Teks
Dodds, Harold W., author
McGraw-Hill, 1962
Buku Teks
Biggs, John B., author
McGraw-Hill, 2011
Buku Teks
edited by Heather Fry, Steve Ketteridge and Stephanie Marshall
Routledge, 2009
Buku Referensi