1. Bridgen HP, Staby GL (1984) in Evans D.A., Sharp W.R., Ammirato P.V., Yamada Y.: Handbook of plant cell culture, volume 1, Macmillan, New-York: 816?827.
2. Caplin SM (1959) Am J Botany, 46: 324?329
3. Chen THH, Kartha KK, Constabel F, Gusta LV (1984) Plant Physiol., 75: 720?725
4. Dougall KD (1980) in Staba J.: Plant tissue culture as a source of biochemicals, CRC Press, Inc Boca Raton, Florida: 115?122
5. Farnsworth NR, Blomster RN, Damratoskid D, Meer WA, Cammarato LV (1964) Lloydia, 27: 302?314.