1. Arditti J (1992) Fundamentals of orchid biology. Wiley, New York
2. Rasmussen FN (1995) Terrestrial orchids – from seed to mycotrophic plant. Cambridge University Press, Cambridge
3. Batygina TB, Andronova EV (2000) The orchid protocorm: an opinion. In: Mukerji K (ed) Glimpses in botany. APH Publishing Corporation, New Delhi, pp 60–77
4. Vinogradova TN, Andronova EV (2002) Development of orchid seeds and seedlings. In: Kull T, Arditti J (eds) Orchid biology: reviews and perspectives, VIII. Kluwer Academic Publishers, Dordrecht, pp 167–234
5. Andronova EV (2006) Embryogenesis in Orchidaceae. In: Batygina TB (ed) Embryology of flowering plants: terminology and concepts, vol 2 seed. Science Publishers, Enfield, pp 355–363