Alpert, Paul
The Free Press, 1973
Buku Teks
MacKendrick, Paul, 1914-
St Martin's Press, 1962
Buku Teks
Camp, L. Sprague de, author
Holt, Rinehart & Winston, 1952
Buku Teks
Brodrick, Alan Houghton
Oxford University Press, 1942
Buku Teks
Senior, Michael, author
Longman, 1979
Buku Teks