Posner, Richard A., author
Litle, Brown, 1980
Buku Teks
Little, Brown , 1980
Buku Teks
Crum, William Leonard
University of California Press, 1953
Buku Teks
Owens, Richard Norman
Prentice-Hall, 1951
Buku Teks
Shriver, Sargent, author
Harper & Row, 1964
Buku Teks