"American aboriginal Architecture." Johnson's Encyclopedia, Vol. I.

"Ancient Society." New York, 1877.

Hubert Howe Bancroft. "The Native Races of the Pacific States." 5 vols. N. York, 1875.

John D. Baldwin. "Ancient America." New York, 1872.

José M. Melgar Y Serrano. "Exámen comparativo entre los Signos simbólicos, &c." Vera Cruz, 1872.

Gustav Brühl. "Die Culturvölker Alt-Amerika's." New York, Cincinnati, and St. Louis, 1876, 1877, and 1878.

Adolph Bastian. "Die Culturlaender des alten America's." Berlin, 1878. 2 vols.

John T. Short. "The North Americans of Antiquity." New York, 1879.

I further refer to papers in

"Nouvelles Annales Des Voyages." 1843. By H. Ternaux-Compans.