Jens Gramm Till Nierhoff Till Tantau Perfect Path Phylogeny Haplotyping with Missing Data Is Fixed-Parameter Tractable. 174-186 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3162&spage=174 2004 conf/iwpec/2004 IWPEC db/conf/iwpec/iwpec2004.html#GrammNT04