1. Ammirato, P.V. (1977). Hormonal control of somatic embryo development from cultured caraway. Plant Physiol. 59: 579–586.
2. Ammirato, P.V. (1983). Embryogenesis. In: Handbook of Plant Cell Culture, Vol. 1. D.A. Evans, W.R. Sharp, P.V. Ammirato, and Y. Yamada (eds.), Macmillan, New York, pp. 82123.
3. Ball, E. (1946). Development in sterile culture of stem tip and adjacent regions of Tropaeolum majus L. and of Lupinus majus L. Am. J. Bot. 33: 301–318.
4. Bagni, N. and Biondi, S. (1987). Polyamines. In: Cell and Tissue Culture in Forestry, Vol. 1.
5. J.M. Bonga and D.J. Durzan (eds.), Martinus Nijhoff Publishers, Dordrecht, pp. 113–124.