Teguh Widodo, Indang Dewata, Iswandi Umar, Ramadhani. “ORRELATION BETWEEN LIFE EXPECTANCY AND PERCENTAGE POPULATION OVER 65 YEARS”. PalArch’s Journal of Archaeology of Egypt Egyptology, vol. 17, no. 7, Nov. 2020, pp. 5108-17, https://archives.palarch.nl/index.php/jae/article/view/2631.