@article{10_4064_aa_61_2_199_208,
     author = {Jacek Fabrykowski},
     title = {Squares in difference sets},
     journal = {Acta Arithmetica},
     pages = {199--208},
     publisher = {mathdoc},
     volume = {61},
     number = {2},
     year = {1992},
     doi = {10.4064/aa-61-2-199-208},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-61-2-199-208/}
}