1. The Standard Encyclopedia of Horticulture;Bailey,1914
2. After-ripening, germination and storage of certain roseaceous seeds;Crocker;Contributions to the Boyce Thompson Institute,1931
3. Factors affecting fruit and seed set in the hybrid tea-rose ‘Sonia’;Dubois;Acta Horticulturae,1988
4. Seeds of woody plants in the United States;Gill,1974
5. Seed manual for ornamental trees and shrubs;Gordon;Forestry Commission Bulletin (London),1982