Strong, Frank R., author
Dennis & Co., 1950
Buku Teks
Fairman, Charles, author
Henry Holt and Company, 1948
Buku Teks
Dowling, Noel T., author
Foundation Press, 1954
Buku Teks
Tribe, Laurence H., author
Foundation Press, 1978
Buku Teks
Oceana Publications, 1958
Buku Teks