Racskó, J., Z. Szabó, D. D. Miller, M. Soltész, and J. Nyéki. “Sunburn Incidence of Apples Is Affected by Rootstocks and Fruit Position Within the Canopy But Not by Fruit Position on the Cluster”. International Journal of Horticultural Science, vol. 15, no. 4, Sept. 2009, pp. 45-51., doi:10.31421/IJHS/15/4/839.