edited by Charles A. Harper
McGraw-Hill, 1972
Buku Referensi
Trulove, James, author
McGraw-Hill, 2000
Buku Teks
Marks, Trevor E., author
William Ernest, 1992
Buku Teks
Mahoney, Edward F., author
Pearson/Prentice Hall, 2006
Buku Teks
Maybin, Harry B., author
McGraw-Hill, 1995
Buku Referensi