1. Improved ASHRAE model to predict hourly and daily solar radiation components in Botswana, Namibia, and Zimbabwe;Nijigorodov;WREC,1996
2. A modification of the ASHRAE clear sky irradiation model;Machler;ASHRAE Transactions,1985
3. Estimation of hourly solar radiation for India;Parishwad;Renewable Energy,1997
4. Dynamic global to direct conversion models;Perez;ASHRAE Transactions,1990