Wolf, John B.
Harper Torchbooks, 1963
Buku Teks
Quelsch, John A.
Prentice-Hall, 1989
Buku Teks
Quelch, John A., author
Prentice-Hall, 1989
Buku Teks
Crank, John
Oxford Univ. Press , 1962
Buku Teks
Brogan, D.W. (Denis William), author
Time, 1960
Buku Teks