Keirstead, Burton Seely, author
Oxford University Press, 1956
Buku Teks
Simul Press, 1976
Buku Teks
Blum, Robert
McGraw-Hill, 1966
Buku Teks
Stebbins, Richard P.
Harper & Brothers, 1955
Buku Teks
edited by Allan Nevins and Louis M. Hacker
D.C. Heath, 1943
Buku Teks