1. Carslaw, H. S., , J. C., Jaeger, , Conduction of Heat in Solids, 2nd. Ed. Clarendon Press, Oxford, 1959,
2. Het warmtegeleidingsvermogen van grond;de Vries;Mededel. Landbouwhogeschool Wageningen,1952
3. Bull. inst. intern. froid, Annexe;de Vries,1952
4. The measurement and recording of the heat flux into the soil;Deacon;Quart. J. Roy. Meteorol. Soc.,1950
5. A new heat-flow meter;Hatfield;J. Sci. Instr.,1950