@article{10_4064_sm_23_1_85_103,
     author = {H. Marcinkowska},
     title = {On the differentiability of weak solutions of certain non-elliptic equations {II}},
     journal = {Studia Mathematica},
     pages = {85--103},
     year = {1963},
     volume = {23},
     number = {1},
     doi = {10.4064/sm-23-1-85-103},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-23-1-85-103/}
}