Belize - Guatemala Relations - Belize government site gives background of issue, structure of National Advisory Commission, and official documents and speeches.
Belize - Guatemala Territorial Differendum - Organization of American States. Includes documents, press releases, and texts of speeches. Most available in English and Spanish.
The Cost of Conflict: Anglo-Belize/Guatemala Territorial Issue - Master's thesis by Janine Sylvestre examines historical relations between the two nations, as well as their current cultures and forms of governments, and suggests courses for the future. (May 10, 1995)
Belize (British Honduras) - Guatemala Border - US Department of State International Boundary Study. Gives background of the dispute, relevant treaties, and details of boundary segments. [PDF] (July 21, 1961)