?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Kent%2C+Phillip&rft.aufirst=Phillip&rft.aulast=Kent&rft.atitle=Characterizing+the+use+of+mathematical+knowledge+in+boundary+crossing+situations+at+work&rft.title=Mind%2C+Culture+and+Activity&rft.volume=14&rft.pages=64-82&rft.date=April+2007&rft.issue=1-2&rft.issn=1074-9039&rft.genre=article