Clapp Hall - Room L9. Center for Instructional Development & Distance Education, University of Pittsburgh. 2009-12-23 [2010-08-13]. (原始内容存档于2010-07-10).
Clapp Hall - Room L9. Center for Instructional Development & Distance Education, University of Pittsburgh. 2009-12-23 [2010-08-13]. (原始内容存档于2010-07-10).