1. Bitters, W. P., Murashige, T., Rangan, T. S., nauer, E.: Investigations on established virus-free citrus plants through tissue culture. Calif. Citrus Nurserymen's Soc. 9, 27?30 (1970).
2. Button, J., Bornman, C. H.: Development of nucellar plants from unpollinated and unfertilized ovules of the Washington Navel orange in vitro. J. S. Afr. Bot. 37, 127?134 (1971).
3. Murashige, T., Tucker, D. P. H.: Growth factor requirement of Citrus tissue culture. Proc. 1st Int. Citrus Symp. vol. 3, p. 1155?1161, H. D. Chapman, ed. Univ. Calif. Riverside: Publ. Dept. 1969.
4. Rangan, T. S., Murashige, T., Bitters, W. B.: In vitro initiation of nucellar embryos in monoembryonic Citrus. Hort. Sci. 3, 226?227 (1968).
5. Rangan, T. S., Murashige, T., Bitters, W. B.: In vitro studies of zygotic and nucellar embryogenesis in Citrus. Proc. 1st Int. Citrus Symp. vol. 1, p. 226?229, H. D. Chapman, ed. Univ. Calif. Riverside: Publ. Dept. 1969.