Hencl, S., and A. Kauranen. “Sobolev Homeomorphisms in W1,k and the Lusin’s Condition (N) on K-Dimensional Subspaces”. Annales Fennici Mathematici, vol. 42, no. 2, Aug. 2017, pp. 771-97, doi:10.5186/aasfm.2017.4244.