}}</ref><ref>{{cite journal|title=Teaching Recursive Thinking using Unplugged Activities|journal=WTE&TEWorld Transactions on Engineering and Technology Education|volume=19|pages=169–175|year=2021|last1=Kuhail|first1=M. A. |last2=Negreiros|first2=J. |last3=Seffah|first3=A. |url = http://www.wiete.com.au/journals/WTE&TE/Pages/Vol.19,%20No.%202%20(2021)/03-Kuhail-M.pdf}}</ref> Recursion solves such [[recursion|recursive problems]] by using [[function (computer science)|functions]] that call themselves from within their own code. The approach can be applied to many types of problems, and recursion is one of the central ideas of computer science.<ref>{{cite book
