Lassi, Z.S.;                     Naseem, R.;                     Salam, R.A.;                     Siddiqui, F.;                     Das, J.K.    
        The Impact of the COVID-19 Pandemic on Immunization Campaigns and Programs: A Systematic Review. Int. J. Environ. Res. Public Health 2021, 18, 988.
    https://doi.org/10.3390/ijerph18030988
    AMA Style
    
                                Lassi ZS,                                 Naseem R,                                 Salam RA,                                 Siddiqui F,                                 Das JK.        
                The Impact of the COVID-19 Pandemic on Immunization Campaigns and Programs: A Systematic Review. International Journal of Environmental Research and Public Health. 2021; 18(3):988.
        https://doi.org/10.3390/ijerph18030988
    
    Chicago/Turabian Style
    
                                Lassi, Zohra S.,                                 Rabia Naseem,                                 Rehana A. Salam,                                 Faareha Siddiqui,                                 and Jai K. Das.        
                2021. "The Impact of the COVID-19 Pandemic on Immunization Campaigns and Programs: A Systematic Review" International Journal of Environmental Research and Public Health 18, no. 3: 988.
        https://doi.org/10.3390/ijerph18030988
    
    APA Style
    
                                Lassi, Z. S.,                                 Naseem, R.,                                 Salam, R. A.,                                 Siddiqui, F.,                                 & Das, J. K.        
        
        (2021). The Impact of the COVID-19 Pandemic on Immunization Campaigns and Programs: A Systematic Review. International Journal of Environmental Research and Public Health, 18(3), 988.
        https://doi.org/10.3390/ijerph18030988