Racskó, József. “N-Phenyl-Phthalamic Acid and Fertilization Effects on Flowering, Fruit Set and Fruit Quality of Apple (Malus Domestica Borkh.)”. Acta Agraria Debreceniensis, no. 24, Oct. 2006, pp. 24-28, https://doi.org/10.34101/actaagrar/24/3220.