1. Performance of flat-plane solar energy collectors;Hottel,1954
2. Operating experience with solar water heating;Heywood;J. Instn Heat. Vent. Eng.,1971
3. Utilization of sun and sky radiation for heating and cooling of buildings;Yellott;ASHRAE Jl,1973
4. Availability of direct, total and diffuse solar radiation to fixed and tracking collectors in the USA;Boes,1977
5. The inter-relationship and characteristic distribution of direct, diffuse and total solar radiation;Liu;Sol. Energy,1960