@book{255647,
	author = {Arthur F. Coxford, James T. Fey, Christian R. Hirsch, Harold L. Schoen, Gail Burrill, Erick W. Hart, Anne E. Watkins},
	title = {Contemporary mathematics in context, a unified approach},
	publisher = {Everyday learning corporation},
	year = {1997},
	address = {Chicago}
}