Simpson (James H.), Journal of a Military Reconnoissance from Santa Fé to the Navajo Country. Philadelphia, 1852.
Simpson (James H.), The Shortest Route to California. Philadelphia, 1869.
Simpson (Thomas), Narrative of the Discoveries on the North Coast of America. London, 1843.
Sitgreaves (L.), Report of an Expedition down the Zuñi and Colorado Rivers. (32d Cong., 2d Sess., Senate Ex. Doc. 59.) Washington, 1853.
Sitjar (Buenaventura), Vocabulario de la Lengua de los Naturales de la Mision de San Antonio, Alta California. (Shea's Linguistics, No. 7.) New York, 1861.
Sivers (Jegór von), Ueber Madeira und die Antillen nach Mittelamerika. Leipzig, 1861.
Smart (Charles), Notes on the Tonto Apaches. In Smithsonian Report, 1867.
Smith (Buckingham), Coleccion de Varios Documentos para la Historia de la Flórida y Tierras Adyacentes. Madrid, 1857. 4to.
Smith (Buckingham), A Grammatical Sketch of the Heve Language. (Shea's Linguistics, No. 3.) New York, 1861.
Smith (Charles Hamilton), The Natural History of the Human Species. London, 1859.