Williams, Robert I., editor
Prentice-Hall, 1956
Buku Referensi
Catur Sasongko, author
Salemba Empat, 2018
Buku Teks
Fess, Philip E., author
Erlangga, 1999
Buku Teks
Swanson, Robert M., author
South-Western Publ. , 1987
Buku Teks
Shillinglaw, Gordon
Il. Richard D. Irwin , 1989
Buku Teks