Harrington, J.F. Sources of fertilizer minerals in South America; a preliminary study - Reston, VA U.S. Geological Survey 1966 - 66 p. ilus. - U.S. Geological Survey Bulletin n.1240 . Subjects--Topical Terms: AZUFREEVAPORITASFERTILIZANTESFOSFATOSGENESIS-YACIMIENTOGEOLOGIA ECONOMICAPOTASIO Subjects--Geographic Terms: AMERICA DEL SUR