Mushtaq, Saadiya, Nasir Ud Din, Abid Hussain Shah, Omair Riaz, Khalid Azam, and Sara Waqar Khan. 2022. “Association of Time-Lines of COVID-19 Seropositivity With Antibody Ratio Levels”. Pakistan Armed Forces Medical Journal 72 (3):1023-26. https://doi.org/10.51253/pafmj.v72i3.7173.