Cornetee, Wendell H., author
McKnight, 1952
Buku Teks
Fowler, Richard J., author
McGraw-Hill, 2003
Multimedia
Fowler, Richard J., author
McGraw-Hill , 2003
Buku Teks
McGraw-Hill Glencoe, 2001
Multimedia
United State Goverment Printing Office, 1960
Buku Teks