@article{10_4064_sm_40_2_183_198,
     author = {W. S{\l}owikowski},
     title = {Range of operators and regularity of solutions},
     journal = {Studia Mathematica},
     pages = {183--198},
     publisher = {mathdoc},
     volume = {40},
     number = {2},
     year = {1971},
     doi = {10.4064/sm-40-2-183-198},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-40-2-183-198/}
}