@article{10_4064_sm181_1_2,
     author = {G. A. Karagulyan},
     title = {A complete characterization of 
$R$-sets in the theory of differentiation of integrals},
     journal = {Studia Mathematica},
     pages = {17--32},
     year = {2007},
     volume = {181},
     number = {1},
     doi = {10.4064/sm181-1-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm181-1-2/}
}