Krebs, Dennis, author
Harcourt Brace Jovanovich, 1988
Buku Teks
Jacobs, Marius, author
Springer-Verlag, 1981
Buku Teks
Lakin, Martin
McGraw-Hill, 1972
Buku Teks
London : William Clowes and Sons Ltd
Majalah, Jurnal, Buletin
edited by Stephen Spender, Irving Kristol and Melvin J. Lasky
Simon and Schuster, 1965
Buku Teks