Razzaq, Zubia, M, Mazhar Hussain, Shahab Naqvi, and Mohammad Aslam. 2009. “CORRELATION OF PLASMA ENDOTHELIN-1 LEVELS WITH PULMONARY HYPERTENSION AFTER INHALED NITRIC OXIDE THERAPY”. Journal of Ayub Medical College Abbottabad 21 (3):106-10. https://jamc.ayubmed.edu.pk/index.php/jamc/article/view/3229.