"Water Resources Assessment of El Salvador"(PDF). United States Army Corps of Engineers (USACE). October 1998. pp.6, A-2, A-19, A-23 –A-24, A-31 –A-33. Archived from the original(PDF) on March 1, 2014. Retrieved 8 October 2013.
"Water Resources Assessment of El Salvador"(PDF). United States Army Corps of Engineers (USACE). October 1998. pp.6, A-2, A-19, A-23 –A-24, A-31 –A-33. Archived from the original(PDF) on March 1, 2014. Retrieved 8 October 2013.