Map showing telegraph and telephone lines in operation ... 1911-1912
Puerto Rico -- Maps
Map showing telegraph and telephone lines in operation, by the Insular Government to accompany Annual Report, 1911-1912. June 30, 1912.
Puerto Rico. Department of the Interior.
Annual Reports, War Department. Report of the Governor of Porto Rico. Washington Government Printing Office: 1912. Insert.
In public domain
Puerto Rico, 1912