1Steward FC, Mapes MO, Hears K. 1958. Growth and organized development of cultured cells. Ⅱ. Growth and division of freely suspended cells. American Journal of Botany, 45 (10) : 705- 708
2Button J, Botha CEJ 1975. Enzymic maceration of citrus callus and the regeneration of plant from single cells. Journal of Experimental Botany, 26(94): 723-729