1) Siu-Hang Li and Wai-Sum Chan, (2004). Estimation of complete period life tables for Singaporeans, Journal of Actuarial practice, Vol. 11, 129- 146 2) Marielynn E. Chanco, (2016). "Mortality Rates Estimation UsingWhittaker-Henderso GraduationTechnique". Social Security System, Quezon City, Philippines, Journal of the Mathematical Society of the Philippines, Vol. 39 Special Issue (2016) pp. 7-16 3) Debon A, Montes F, and Sala R. (2006). "A Comparison of Nonparametric Methods in the Graduation of Mortality: Application to Data from the Valencia Region (Spain)". International Statistical Review, Vol 74, 2, pp.215–233. 4) Frank E. Knorr. (1984). "Multidimensional Whittaker- Henderson graduation". Transactions of Society of actuaries International Statistical, Vol 36, pp.213–255. 5) Takis Papaioannou and Athanasios Sachlas. (2004). "Graduation of mortality rates revisited". University of Piraeus. 6) London, D. (1985). Graduation: The Revision of Estimates, ACTEX Publications,Winsted, Connecticut. 7) Walter B. Lowrie. (1982)" An Extension of the Whittaker-Henderson Method of Graduation", Transactions of Society of Actuaries, Vol. 34, pp. 329–372. 8) Johnny Siu-Hang Li, Mary R. Hardy, and Ken Seng Tan. (2008)" Threshold Life Tables and Their Applications ", North American Actuarial Journal, Vol. 12, Number 2, Published online: 28 Dec 2012, pp. 99–115. 24 9) Whittaker. mortality Table .R, Smooth a life table using the WhittakerHenderson method 10) Miller M.D. (1946). Elements of Graduation. New York: Actuarial Society of America and American Institute of Actuaries. 11) Reinhold Kainhofer (2018). R package A Framework for various Types of Mortality/ Life Tables (Mortality Tables).