Teguh Widodo, Indang Dewata, Iswandi Umar , Ramadhani. “CORRELATION BETWEEN LIFE EXPECTANCY AND PERCENTAGE POPULATION OVER 65 YEARS”. PalArch’s Journal of Archaeology of Egypt Egyptology, vol. 17, no. 6, Dec. 2020, pp. 8863-71, https://archives.palarch.nl/index.php/jae/article/view/2338.