Hajo Broersma Fedor V. Fomin Rastislav Kralovic Gerhard J. Woeginger Eliminating graphs by means of parallel knock-out schemes. 92-102 2007 155 Discrete Applied Mathematics 2 http://dx.doi.org/10.1016/j.dam.2006.04.034 db/journals/dam/dam155.html#BroersmaFKW07