@book{1870,
	author = {Wrightson, Katherine. and Merlino, Joseph.},
	title = {Introduction to UNIX. /},
	publisher = {McGraw-Hill,},
	year = {2003.},
	address = {Boston :},
	url = {http://www.loc.gov/catdir/toc/mh031/2002030944.html}
}