Piejko, Krzysztof, and Lucyna Trojnar-Spelina. “On (k_1A_1, k_2A_2, k_3A_3)-Edge Colourings in Graphs and Generalized Jacobsthal Numbers”. Annales Mathematicae Silesianae 39, no. 2 (April 26, 2025): 331–348. Accessed December 5, 2025. https://journals.us.edu.pl/index.php/AMSIL/article/view/18817.