@book{124351,
	author = {Zelenyuk, Yevhen G. and ebrary, Inc.},
	title = {Ultrafilters and topologies on groups},
	publisher = {De Gruyter,},
	year = {c2011.},
	series = {De Gruyter expositions in mathematics,},
	address = {Berlin ;},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10486427}
}