S. Ahmed, M., A. Mohammed, and N. E. Arif. “Hosoya Polynomial, Wiener Index, Coloring and Planar of Annihilator Graph of Zn”. AL-Rafidain Journal of Computer Sciences and Mathematics, vol. 14, no. 2, Dec. 2020, pp. 41-52, doi:10.33899/csmj.2020.167337 .