@book{23046,
	author = {Varchenko, A. N. and Etingof, P.I. and Etingof, P. I. ; jt.auth.},
	title = {Why the boundary of a round drop becomes a curve of order four},
	publisher = {American Mathematical Society},
	year = {1969},
	address = {Providence},
	note = {AMS Webpage}
}