1. Heat exchange penalties in double loop solar water heating systems;de Winter;Solar Energy,1975
2. Calculation of monthly average insolation on tilted surfaces;Klein;Solar Energy,1977
3. Retrofitting: plan, action and early results using the townhouses at Twin Rivers;Harrje;Center for Environmental Studies, Princeton University Report No. 29,1976
4. Heat pumps;Mitchell;Solar Age,1978
5. T. L. Freeman, (personal communication, 1978).