Park, William R., author
John Wiley & Sons, 1978
Buku Teks
Heath, Joseph, author
Capstone, 2005
Buku Teks
Elliot, Rose, author
Chapmans Publisher Ltd., 1994
Buku Referensi
Minrath, William R., author
D. Van Nostrand, 1956
Buku Teks
Greene, Gardiner G., author
McGraw-Hill, 1975
Buku Teks