References
- 1. The United States Department of Agriculture: After a hundred years; The Yearbook of Agriculture 1962, pp. 688, The U.S. Government Printing Office, Washington, D.C., 1962.
- 2. Tso, T.C.: Physiology and biochemistry of tobacco plants; Dowden, Hutchinson & Ross, Inc., Strouds-burg, Pennsylvania, USA, 1972.
- 3. Tso, T.C.: Production, physiology, and biochemistry of tobacco plant; International Institute of Develop-ment and Education in Agriculture and Life Sciences (IDEALS), Beltsville, Maryland, USA, 1990.