Brand, W.
The Free Press, 1958
Buku Teks
Casson, Herbert N.
London The Efficiency Maya time [date of publication not identified],
Buku Teks
Berlin Akedemie [t.th.]
Buku Teks
Gao, Zhiguo
London Graham & Trotman 1994,
Buku Teks
Brand, W.
Free Press, 1958
Buku Teks