Treaties and other international acts series. 3441. Health and sanitation, cooperative program in Colombia, agreement between United States and Colombia, extending agreement of Sept. 15 and Oct. 20, 1950, as supplemented, effected by exchange of notes signed Bogota Apr. 5, May 2 and 31, 1955, and agreement between Government of Colombia and Institute of Inter-American Affairs signed Bogota June 10, 1955 [entered into force June 10, 1955].