RIddle, K. Wilkinson
London Arco 1962
Buku Referensi
Humphreys, Christmas
Curzon Press, 1994
Buku Referensi
Andrew N. Weintraub, editor
Routledge, 2011
Buku Teks
Wannan, Bill, compiler
Lansdowne, 1976
Buku Referensi
London: Tiger Books International, 1994,
Buku Referensi