The Power of Commuting with Finite Sets of Words.

Michal Kunc The Power of Commuting with Finite Sets of Words. 569-580 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3404&spage=569 2005 conf/stacs/2005 STACS db/conf/stacs/stacs2005.html#Kunc05