Esho, Kamal B., et al. “EFFECT OF SOAKING SEEDS IN ZINC SULPHATE SOLUTION ON VEGETATIVE GROWTH , FLOWERING AND YIELD , OF TWO CULTIVARS OF PEA (Pisum Sativum L. ) . ”. Diyala Agricultural Sciences Journal , vol. 1, no. 2, Dec. 2009, pp. 66-77, https://journal.djas.uodiyala.edu.iq/index.php/dasj/article/view/3171.