Confidential Memo re: Ambassador Whelan, August 8, 1957
in General Records of the Department of State, 1763 - 2002 (RG59). Records Relating to Costa Rica, 1958 - 1962 (A1 3158), of United States. National Archives and Records Administration. Federal Records (1957), Box 1, Costa Rica-Nicaragua Boundary Dispute [Lot 65D24] , 4 page(s)