edited by Charles K. Warner
Macmillan, 1966
Buku Teks
Butterfield, Herbert
The Free Press , 1957
Buku Teks
Partridge, Eric, 1894-1979, author
Routledge, 1991
Buku Referensi
edited by Jean-Jacques Hublin, Shannon P. McPherron
Springer Science, 2012
eBooks
Hirschmeier, Johannes
Harvard University Press, 1964
Buku Teks