@article{10_4153_CMB_1989_001_1,
     author = {Robertson, E. F. and Williams, P. D.},
     title = {Efficient {Presentations} of the {Groups} {PSL(2,} 2p) and {SL(2,} 2p)},
     journal = {Canadian mathematical bulletin},
     pages = {3--10},
     year = {1989},
     volume = {32},
     number = {1},
     doi = {10.4153/CMB-1989-001-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1989-001-1/}
}