1. Tulip forcing;A.D.A.S. (Agricultural Development and Advisory Service),1977
2. Internal Stages of Bulb Development;A.D.A.S. (Agricultural Development and Advisory Service),1980
3. Modern Potting Composts;Bunt,1976
4. A research on the possibility of using gibberellin for tulip forcing;Cocozza Talia;Acta Hortic.,1980
5. Developmental stages of flower formation in tulips, narcissi, irises, hyacinths and lilies;Cremer;Meded. Landbouwhogesch. Wageningen,1974