“The Study of Serum Vitamin D Level In Patient With Pulmonary Hypertension And Right Ventricular Systolic Dysfunction Detected by Transthoracic Echocardiography”, JUBPAS, vol. 26, no. 5, pp. 86–94, Mar. 2018, Accessed: May 03, 2025. [Online]. Available: https://www.journalofbabylon.com/index.php/JUBPAS/article/view/863