Byun, S.-S., D. K. Palagachev, and L. G. Softova. “Global Gradient Estimates in Weighted Lebesgue Spaces for Parabolic Operators”. Annales Fennici Mathematici, vol. 41, no. 1, Feb. 2016, pp. 67-83, doi:10.5186/aasfm.2016.4102.