@article{10_4064_cm_57_1_103_115,
     author = {Dogan \c{C}\"omez},
     title = {Linear modulus of a multidimensional semigroup of $L_1$-contractions and a differentiation theorem},
     journal = {Colloquium Mathematicum},
     pages = {103--115},
     publisher = {mathdoc},
     volume = {57},
     number = {1},
     year = {1989},
     doi = {10.4064/cm-57-1-103-115},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-57-1-103-115/}
}