List of Articles Abbas Heydari Article 1 - Balaban Index of C4C8(S) Nanotubes 20.1001.1.25382217.2020.14.2.7.1 Abbas Heydari Theory of Approximation and Applications , Issue 1 , Year , Spring 2020 Article 2 - A new method for computation of Wiener index if C4C8(S) Nanotorus 20.1001.1.25382217.2021.15.1.6.5 Abbas Heydari Theory of Approximation and Applications , Issue 1 , Year , Winter 2021 Article 3 - On the computation of characteristic polynomials and spectra of balanced rooted trees 20.1001.1.25382217.2020.14.1.12.4 Abbas Heydari Theory of Approximation and Applications , Issue 1 , Year , Winter 2020