Habibi Vosta Kolaei, M. J., and S. Azami. “First Eigenvalue of P-Laplacian Along The Normalized Ricci Flow on Bianchi Classes”. Journal of the Indonesian Mathematical Society, vol. 26, no. 3, Nov. 2020, pp. 380-92, doi:10.22342/jims.26.3.934.380-392.