@book{33191,
	author = {Harwit, Martin. and SpringerLink (Online service)},
	title = {Astrophysical Concepts},
	publisher = {Springer New York,},
	year = {2006.},
	series = {Astronomy and Astrophysics Library,},
	address = {New York, NY :},
	edition = {Fourth Edition.},
	url = {http://dx.doi.org/10.1007/978-0-387-33228-4}
}