@book{31520,
	author = {Williams, Marcia L. and Paprock, Kenneth.},
	title = {Distance learning :},
	publisher = {Sage,},
	year = {c1999.},
	address = {Thousand Oaks, Calif. :},
	url = {http://www.loc.gov/catdir/enhancements/fy0656/98233173-d.html}
}