Canfield, Leon H.
Houghton Mifflin, 1954
Buku Teks SO
Funston, Richard Y.
Schenkman Publishing Company, Inc., 1977
Buku Teks
Quarles, Benjamin
Macmillan, 1969
Buku Teks SO
Nevins, Allan, 1890-1971
Macmillan, 1927
Buku Teks SO
Rippy, J. Fred
University of Michigan Press, 1958
Buku Teks SO