Decker, William Merrill
University of North Carolina Press, 1990
Buku Teks
Van Gorp, Trevor, author
Elsevier, 2012
Buku Teks
Bemis, Samuel Flagg, 1891-1973, author
Alfred A. Knopf, 1949; 1956
Buku Teks
Donnelly, Thomas C.
The University of Mexico Press, 1953
Buku Teks
Carlor, Manuel L
Praeger, 1974
Buku Teks