1. United Nations, 1980a. Solar Energy. Rep. Tech. Panel second session (A/CONF. 100/PC/27), 10 February.
2. United Nations, 1980b. Geothermal Energy. Rep. Tech. Panel, second session (A/CONF. 100/PC/23), 11 December.
3. United Nations, 1980c. Wind Energy. Rep. Tech. Panel, second session (A/CONF. 100/PC/24), 10 December.
4. United Nations, 1981a. Fuelwood and Charcoal. Rep. Tech. Panel, second session (A/CONF. 100/PC/34), 25 February.