@book{10206,
	author = {Polish Academy of Sciences, Institution of Mathematics and Balcerzyk, Stanislaw ; ed.},
	title = {Topics in algebra; proceedings of the 31st semester, held at the Stefan Banach International Mathematical Center in Warsaw from Feb. 15 June 15, 1988},
	publisher = {Polish Scientific Publishers},
	year = {1990},
	series = {Banach Center Publications},
	address = {Warszawa}
}