Rotkiewicz, Andrzej. “On Lucas Numbers, Lucas Pseudoprimes and a Numbertheoretical Series Involving Lucas Pseudoprimes and Carmichael Numbers”. Annales Mathematicae Silesianae, vol. 21, Sept. 2007, pp. 49-60, https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14063.