1. Action additive de temperature froide continues sur le processus preparatoire a la floraison chez trois clones de Festuca arundinacea Screb;Blondon;Comptes Rendu Hebdomadaires de Séances de ľAcademie des Sciences, S. D,1971
2. Effect of heavy and late application of nitrogenous fertilizer on the cold resistance of Kentucky bluegrass;Carroll;Plant Physiology,1939
3. Frost avoidance and frost resistance in Centrosema Virginianum;Clements;Journal of Applied Ecology,1977
4. Hewitt , E. J. 1966 Sand and water culture methods used in the study of plant nutrition Commonwealth Bureau of Horticulture and Plantation Crops, Technical Communication