1. Allen, R.M., McComb, A.L., 1956. Rooting of cottonwood cuttings. USDA For. Serv., Southern For. Exp. Sta. Occasional Paper 151, 10 pp.
2. Anonymous, 1982. Average Frost-free Days. Alberta Bureau of Surveying and Mapping, Edmonton, Canada.
3. Qualité des boutures de peuplier;Berthelot;Informations-Forêt, Afocel Armef,1990
4. Root formation of black cottonwood cuttings in relation to region of parent shoot;Bloomberg;For. Chron,1959
5. Seasonal variation in propagability of dormant balsam poplar cuttings;Cunningham;Plant Propagat,1984