@article{MS2_1983__52_166826,
     author = {J.H.E. Cohn},
     title = {Squares in arithmetical progressions {I.}},
     journal = {Mathematica Scandinavica},
     pages = {5--19},
     publisher = {mathdoc},
     volume = {52},
     year = {1983},
     zbl = {0511.10014},
     url = {http://geodesic.mathdoc.fr/item/MS2_1983__52_166826/}
}