@article{KraKrnKupLuzVol12,
   author = {Kr\'{a}l, D. and Krnc, M. and Kupec, M. and Lu\v{z}ar, B. and Volec, J.},
   title = {Extending fractional precolorings},
   journal = {SIAM J. Discrete Math.},
   volume = {26},
   number = {2},
   pages = {647--660},
   DOI = {10.1137/110828988},
   url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84865621602&partnerID=MN8TOARS},
   year = {2012}
}