Frank Niedermeyer Saharon Shelah Karsten Steffens The <i>f</i>-factor Problem for Graphs and the Hereditary Property. 665-672 2006 45 Arch. Math. Log. 6 http://dx.doi.org/10.1007/s00153-006-0009-z db/journals/aml/aml45.html#NiedermeyerSS06