Ambika Roy Bardhan,  Demographic and Socio-Economic Study of the Elderly Population in Kolkata, India.   journal   = {International Journal of Humanities and Social Sciences}, [online]. World Academy of Science, Engineering and Technology.
    October 2019, vol. 155(11). 1419 - 1426
    [viewed 28 February 2021]. Available from: https://publications.waset.org/pdf/10010872.