@book{82862,
	author = {Dobey, Daniel C. and Beichner, Robert J.},
	title = {Essentials of elementary science /},
	publisher = {Allyn and Bacon,},
	year = {1999.},
	series = {Essentials of classroom teaching series},
	address = {Needham Heights, MA. :},
	edition = {2nd ed. }
}