N. Akhtar Abbasi, M. M. Kushad, I. Ahmad Hafiz, and M. Maqbool, “Relationship of Superficial Scald Related Fruit Maturity with Polyphenoloxidase and Superoxide Dismutase Activities in Red Spur Delicious Apples”, ajc, vol. 20, no. 8, pp. 5986–5996, Mar. 2010.