@book{17238,
	author = {Fritsch, Rudolf and Fritsch, Gerda and Fritsch, Gerda ; jt. auth.},
	title = {The four-color theorem; history, topological foundations, and idea of proof},
	publisher = {Springer-Verlag},
	year = {1998},
	address = {New York},
	note = {"Purchased under NBHM grant for the year 1998-99"}
}