@article{10_4064_sm_92_3_231_255,
     author = {A. Benkirane and J.-P. Gossez},
     title = {An approximation theorem in higher order {Orlicz-Sobolev} spaces and applications},
     journal = {Studia Mathematica},
     pages = {231--255},
     year = {1989},
     volume = {92},
     number = {3},
     doi = {10.4064/sm-92-3-231-255},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-92-3-231-255/}
}