Martin, Michael Rheta, author
The Bobbs Merrill, 1968
Buku Referensi
Wilgus, A. Curtis, author
Barner & Noble, 1963
Buku Teks
Berry, R. Albert, author
Md. Johns Hopkins University Press , 1979
Buku Teks
Washington, D.C. International Cooperation Administration s.a,
Buku Teks
edited with an introduction by R. A. Humphreys & John Lynch
Alfred A. Knopf, 1966
Buku Teks