@article{LuzSkrTan09,
   author = {Lu\v{z}ar, B. and \v{S}krekovski, R. and Tancer, M.},
   title = {Injective colorings of planar graphs with few colors},
   journal = {Discrete Math.},
   volume = {309},
   number = {18},
   pages = {5636--5649},
   DOI = {10.1016/j.disc.2008.04.005},
   year = {2009}
}