A. G. Ingle, S. D. Deo, P. K. Dhankar, S. Islam, K. Srivastava, and B. Thakran, “Cosmological Model with Polytropic Bulk Viscosity and Varying Gravitational and Cosmological Constants”, East Eur. J. Phys., no. 3, pp. 54-67, Sep. 2026.