CELIK, F., M. GUNDOGDU, S. ERCISLI, B. KAKI, S. BERK, G. ILHAN, and H. I. SAGBAS. “Variation in Organic Acid, Sugar and Phenolic Compounds in Fruits of Historical Apple Cultivars”. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, vol. 46, no. 2, Mar. 2018, pp. 622-9, doi:10.15835/nbha46211160.