Crosskey, William Winslow
The University Chicago Press, 1953
Buku Teks
Walker, Mary M.
General Learning Press, 1974
Buku Teks
Haines, Charles Grove
Russell and Russell, Inc., 1960
Buku Teks
McLaughlin, Andrew C., author
Appleton Century Crofts, 1935
Buku Teks
Swisher, Carl Brent, author
University of Chicago Press, 1946
Buku Teks