1. Acheampong E (1982) Ph.D thesis, University of Birmingham, England
2. Alan JJ (1979) Ph.D thesis, University of Birmingham, England
3. Ascenco JC (1967) Trop Agric (Trinidad) 44:243?244
4. Banerjee N, Vuylsteke D, De Langhe E (1985) In: Withers LA and Alderson PG (ed) Plant Tissue Culture and its Agricultural Applications, Butterworth Scientific Ltd., UK (in press)
5. Bhojwani SS (1981) Physiol Plant 52:187?190