edited by Frank Debenham
McGraw-Hill, 1960
Buku Referensi
Israel, Saul, author
Holt, Rinehart and Winston, 1976
Buku Teks
James, Preston E., author
Macmillan, 1972
Buku Teks
by Les Rowntree ... [and others]
Prentice-Hall, 2011
Buku Teks
Cole, J.P., author
Penguin Books, 1979
Buku Teks