Paper  bibtex   

@article{polonoli_defining_2000,
	title = {Defining the {Role} of the {Digital} {Portfolio} in {Teacher} {Education}.},
	url = {http://www.eric.ed.gov/ERICWebPortal/recordDetail?accno=ED447806},
	urldate = {2013-05-13TZ},
	author = {Polonoli, Keith E.},
	year = {2000}
}