HARPER, G. H. “Biology of Apples and Pears. John E. Jackson. Cambridge: Cambridge University Press. 2003. 500pp. ISBN 0 521 38018 9 (hardback)”. Edinburgh Journal of Botany 61, no. 1 (January 5, 2005): 93–95. Accessed September 3, 2026. https://journals.rbge.org.uk/ejb/article/view/1130.