“On the Direct and Skew Sums of Γ1−Non Deranged Permutations”, Punjab Univ. J. Math., vol. 50, no. 3, pp. 43–51, Sep. 2018, Accessed: Jun. 29, 2025. [Online]. Available: https://pujm.pu.edu.pk/index.php/pujm/article/view/139