Khodzhibekov, M., S. Bahramov, and G. Nazarova. “Assessment of the Severity of Primary (idiopathic) Pulmonary Hypertension According to Echocardiography”. Scientific Collection «InterConf», no. 126, Sept. 2022, pp. 170-1, https://archive.interconf.center/index.php/conference-proceeding/article/view/1368.