@article{10_4153_CMB_1984_057_0,
     author = {Colbourn, Charles J. and Phelps, Kevin T. and R\"odl, Vojt\v{e}ch},
     title = {Block {Sizes} in {Pairwise} {Balanced} {Designs}},
     journal = {Canadian mathematical bulletin},
     pages = {375--380},
     year = {1984},
     volume = {27},
     number = {3},
     doi = {10.4153/CMB-1984-057-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1984-057-0/}
}