Айталиев, Е. ., and . А. . Утегенова. “SOLVING OLYMPIAD PROBLEMS FOR THE FIBONACCI SERIES”. Bulletin of Abai KazNPU. Series of Physical and Mathematical Sciences, vol. 70, no. 2, June 2020, pp. 21-25, doi:10.51889/2020-2.1728-7901.03 .