DOE:10.1511/1998.17.914
DOE:10.1511/2000.29.883
DOE:10.1511/2004.50.949
DOE:10.1511/2005.55.973
DOE:10.1511/2006.62.1008
DOE:10.1511/2007.65.1023
DOE:10.1511/2008.70.3638