@article{10_4153_CMB_1969_039_0,
     author = {Williams, Kenneth S.},
     title = {Small {Solutions} of the {Congruence} ax2 + by2 \ensuremath{\equiv} c(mod k)},
     journal = {Canadian mathematical bulletin},
     pages = {311--320},
     year = {1969},
     volume = {12},
     number = {3},
     doi = {10.4153/CMB-1969-039-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1969-039-0/}
}