1. Calculation of monthly average insolation on tilted surfaces;Klein;Solar Energy,1977
2. Calculation of monthly average insolation on tilted surfaces;Klein;Solar Energy,1978
3. Daily isolation on surfaces tilted towards the equator;Liu;Trans. ASHRAE,1962
4. The estimation of monthly mean values of daily total short wave radiation on vertical and inclined surfaces from sunshine records for latitudes 40°N–40°S;Page,1961
5. Solar Energy Themal Processes;Duffie,1974