Johnson, Elmer D., author
The Scarecrow Press, 1970
Buku Teks
McKay, John P., author
Houghton Mifflin , 1983
Buku Teks
Adams, Laurie Schneider, author
Brown & Benchmark , 1997
Buku Referensi
Fuller, John Frederick Charles, author
Funk and Wagnalls, 1955
Buku Teks
Cheney, L.J, author
The New American Library , 1959
Buku Teks