P. P. Khade, et al. “KantowskiSachs Bulk Viscous String Cosmological Model In Gravity With Time Varying Deceleration Parameter”. Global Journal of Science Frontier Research, vol. 18, no. A1, Jan. 2018, pp. 39-46, https://journalofscience.org/index.php/GJSFR/article/view/101247.