@article{GDZPPN000365300,
title = {The Maximum Number of Second Smallest Distances in Finite Planar Sets.},
journal = {Discrete \& computational geometry},
volume = {7},
year = {1992},
pages = {371-380},
zbl = {0749.52012},
url = {http://dml.mathdoc.fr/item/GDZPPN000365300}
}
Brass, P. The Maximum Number of Second Smallest Distances in Finite Planar Sets.. Discrete & computational geometry, Tome 7 (1992) pp. 371-380. http://gdmltest.u-ga.fr/item/GDZPPN000365300/