Авєкін, Я. В., Н. В. Нужина, and М. М. Гайдаржи. “Structure of Seeds of Succulent Representatives of Apocynaceae Family”. The Journal of V.N.Karazin Kharkiv National University. Series «Biology», Vol. 26, 1, pp. 16-28, https://periodicals.karazin.ua/biology/article/view/6253.