Hunter, G. W. I.; Swartzwelder, J. C.; Redmond, D. L.; Shearer, L. A.; Tonn, R. J.; Vargas Alvarado, R.; Alfaro Brenes, M.; Zúñiga Ríos, J. A.; Rodríguez Montoya, C. A Survey of Three Costa Rican Communities for Intestinal Parasites. Rev. Biol. Trop. 1965, 13, 123–133.