@book{820,
	author = {Hill, C. R.},
	title = {Physical principles of medical ultrasonics /},
	publisher = {John Wiley & Sons,},
	year = {c2004.},
	address = {Chichester ;},
	edition = {2nd ed.},
	note = {Previous ed.: Chichester : Ellis Horwood ; New York : Halstead Press, 1986.},
	url = {http://www.loc.gov/catdir/description/wiley037/2003057609.html}
}