Krishna, T.V. Uday, V Venkateswara Rao, Syed Umer Ahmed, and B. Vishwanath. 2021. “Serum Electrolytes, Acid–base Balance and Need for Non-Invasive Ventilation in Patients With Hypercapnic Acute Exacerbation of Chronic Obstructive Pulmonary Disease”. International Journal of Health and Clinical Research 4 (2):186-89. https://www.ijhcr.com/index.php/ijhcr/article/view/806.