Bernstein, Lewis
Norwalk Appletton century crofts , 1985
Buku Teks
Ewles, Linda
Scutari Press, 1995
Buku Referensi
Bailliere Tindall , 2001
Buku Teks
Schriven, Angela
Elsevier, 2010
Buku Teks SO
Fell-Carlson, Deborah L.
Thomson/Delmar Learning, 2008
Buku Teks