Geographer, Office of Research in Economics and Science, Bureau of Intelligence and Research. «International Boundary Study n° 32 Cambodia – Laos Boundary» (en anglès). The Florida State University: US Department of State, 25-09-2002. Arxivat de l'original el 16 de setembre 2006. [Consulta: 14 gener 2010].
Geographer, Office of Research in Economics and Science, Bureau of Intelligence and Research. «International Boundary Study n° 32 Cambodia – Laos Boundary» (en anglès). The Florida State University: US Department of State, 25-09-2002. Arxivat de l'original el 16 de setembre 2006. [Consulta: 14 gener 2010].