Debris flow and erosion control problems caused by the ash eruptions of Irazu Volcano, Costa Rica - Waldron, Howard Hamilton 1917- (United States Government Printing Office, 1967)
"Contributions to general geology"
"Prepared in cooperation with the Oficina de Defensa Civil and Oficina de Planificacion de Costa Rica under the auspices of he Agency for International Development, U.S. Department of State"