Last, John M., 1926-, author
McGraw-Hill, 1997
Buku Teks
edited by Edwin D. Kilbourne, Wilson G. Smillie
MacMillan company, 1969
Buku Teks
Rogers, Edward S., author
Macmillan, 1960
Buku Teks
edited by Moryteza Honari and Thomas Boleyn
Routledge, 1999
Buku Teks
Hawley, Amos H., author
The University of Chicago Press, 1986
Buku Teks