@book{151273,
	author = {Henschel, Astrid. and ebrary, Inc.},
	title = {German verb tenses},
	publisher = {McGraw-Hill,},
	year = {2006.},
	series = {Practice makes perfect},
	address = {Chicago :},
	url = {http://site.ebrary.com/lib/strathmore/Doc?id=10137227}
}