Varga, D., and L. Udvardy. “Comparative Anatomical Study of Leaf Tissues of Scab Resistant and Susceptible Apple Cultivars”. International Journal of Horticultural Science 16, no. 5 (September 6, 2010): 43–45. Accessed April 18, 2021. https://ojs.lib.unideb.hu/IJHS/article/view/934.