Borchert, Adam, and Narad Rampersad. “Words With Many Palindrome Pair Factors”. The Electronic Journal of Combinatorics 22, no. 4 (October 30, 2015): P4.23. Accessed March 29, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v22i4p23.