Brian Thoms Nathan Garrett Jesus Canelon Herrera Terry Ryan Understanding the Roles of Knowledge Sharing and Trust in Online Learning Communities. 3 2008 conf/hicss/2008 HICSS http://doi.ieeecomputersociety.org/10.1109/HICSS.2008.481 db/conf/hicss/hicss2008.html#ThomsGHR08