Christian Choffrut Massimiliano Goldwurm Violetta Lonati On the Maximum Coefficients of Rational Formal Series in Commuting Variables. 114-126 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3340&spage=114 2004 conf/dlt/2004 Developments in Language Theory db/conf/dlt/dlt2004.html#ChoffrutGL04