A Linear Time Algorithm for <i>L</i>(2, 1)-Labeling of Trees.

Toru Hasunuma Toshimasa Ishii Hirotaka Ono Yushi Uno A Linear Time Algorithm for <i>L</i>(2, 1)-Labeling of Trees. 35-46 2009 ESA http://dx.doi.org/10.1007/978-3-642-04128-0_4 conf/esa/2009 db/conf/esa/esa2009.html#HasunumaIOU09