Simon, Herbert A., author
Alfred A. Knopf, 1973
Buku Teks
Buku Teks
Bartholomew, Paul C., author
Littlefield, Adams, 1959
Buku Teks
Charlesworth, James C. (James Clyde), 1900-, author
Harper, 1951
Buku Teks
Sage Periodeicals Press, 1992
Majalah, Jurnal, Buletin