@article{10_1017_S0017089500002263,
     author = {Ganley, Michael J.},
     title = {Difference sets and planar polarities},
     journal = {Glasgow mathematical journal},
     pages = {99--108},
     year = {1974},
     volume = {15},
     number = {2},
     doi = {10.1017/S0017089500002263},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500002263/}
}