@article{SM_2018_209_11_a2,
     author = {M. R. Gabdullin},
     title = {Sets in $\mathbb{Z}_m$ whose difference sets avoid squares},
     journal = {Sbornik. Mathematics},
     pages = {1603--1610},
     year = {2018},
     volume = {209},
     number = {11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2018_209_11_a2/}
}