1. Solar Radiation During Cloudless Days;Fritz;Heating and Ventilating,1949
2. Average Solar Radiation in the United States;Fritz;Heating and Ventilating,1949
3. A Preliminary Estimate of Average Insolation in Canada;Mateer;Canadian Journal of Agricultural Science,1955
4. The Distribution of Solar Radiation Throughout Southern Africa;Drummond;Journal of Meteorology,1957
5. A Contribution to the Radiation Climatology of Northern Europe;Black;Archiv für Meteorologie, Geophysik und Bioklimatologie, Serie B,1960