00432nas a2200169   4500000000100000000000100001008004100002260003100043100002400074700001800098700001700116700002100133700001600154700001700170245006200187300001300249       2004                            d  bInformation TodayaMedford1 aElisabeth Davenport1 aMariam Ginman1 aYves Marcoux1 aDiane Sonnenwald1 aSanna Talja1 aIsto Vatanen00aThe Concept of the Source in a World of Multiple Channels  a567--568