- Minnesota Ground Frost Study
(Dan Pokorny - St. Cloud State, 1993) - Average Date of Initial Soil Freeze
- Spring Soil Temperatures
(Climate of Minnesota Series Part - IV, 1966) - Calculated and Measured Air and Soil Freeze-Thaw Frequencies
(Journal of Applied Meteorology, 1995)
- The Hydrologic Cycle and Soil Water
(Climate of Minnesota Series - Part XII, 1979)