Marr, Phebe
Colorado Westvies Press, 1985
Buku Teks
Longrigg, Stephen Hemsley, author
Oxford University Press , 1956
Buku Teks
Director-General of guidance and Broadcasting, 1956
Buku Teks
Donaldson, Dwight M., author
Luzac & Company, 1933
Buku Teks
[publisher not identified], [date of publication not identified]
Buku Teks