@book{18220,
	author = {Giaquinta, Mariano and others and Modica, Giuseppe ; jt. auth.},
	title = {Cartesian currents in the calculus of variations I},
	publisher = {Springer-Verlag},
	year = {1998},
	series = {Ergebnisse der Mathematik und ihrer Grenzgebiete},
	address = {Berlin}
}