@book{6622314,
	author = {Фридман, А.},
	title = {Вариационные принципы и задачи со свободными границами},
	publisher = {Наука},
	year = {1990},
	address = {М.},
	note = {Перевод изд.: Variational principles and free-boundary problems / Awner Friedman (New York etc.)}
}