@article{10_4064_sm_9_1_43_53,
     author = {P. Erd\"os and M. Kac and E. van Kampen and A. Wintner},
     title = {Ramanujan sums and almost periodic functions},
     journal = {Studia Mathematica},
     pages = {43--53},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1940},
     doi = {10.4064/sm-9-1-43-53},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-9-1-43-53/}
}