Cooper, R. W.
Penguin Books, [c.1947]
Buku Teks
Roosevelt, Eleanor
Harper & Brothers, 1949
Buku Teks
Priemel, Kim Christian
Oxford University Press, 2016
eBooks
Thompson, Lindsay H. S.
Hyland House, 1989
Buku Teks
Connerton, Paul
Cambridge University Press, 1989
eBooks