Heekyoung Jung Erik Stolterman William Ryan Tonya Thompson Marty Siegel Toward a framework for ecologies of artifacts: how are digital artifacts interconnected within a personal life? 201-210 2008 NordiCHI http://doi.acm.org/10.1145/1463160.1463182 conf/nordichi/2008 db/conf/nordichi/nordichi2008.html#JungSRTS08