Sobol, Z., Liskevich, V., Skrypnik, I. I., Sobol, Z., & Liskevich, V. (2011). Gradient estimates for degenerate quasi-linear parabolic equations. Journal of the London Mathematical Society, 84(2), pp. 446-474. doi:10.1112/jlms/jdr020

Sobol, Zeev, V. Liskevich, I. I. Skrypnik, Z. Sobol, and Vitali Liskevich. "Gradient Estimates for Degenerate Quasi-linear Parabolic Equations." Journal of the London Mathematical Society 84, no. 2 (2011): 446-474.

Sobol, Zeev, et al. "Gradient Estimates for Degenerate Quasi-linear Parabolic Equations." Journal of the London Mathematical Society 84.2 (2011): 446-474.