@article{MAN_1969__180_161800,
     author = {S. ZN\'AM},
     title = {On {Exactly} {Covering} {Systems} of {Arithmetic} {Sequences.}},
     journal = {Mathematische Annalen},
     pages = {227--232},
     publisher = {mathdoc},
     volume = {180},
     year = {1969},
     zbl = {0169.37405},
     url = {http://geodesic.mathdoc.fr/item/MAN_1969__180_161800/}
}