@book{15629,
	author = {HADLEY, G. and KEMP, M. C.},
	title = {Variational methods in economics /},
	publisher = {North Holland,},
	year = {1971.},
	address = {Amsterdam :},
	url = {http://koha.tu.koszalin.pl/cgi-bin/koha/opac-detail.pl?biblionumber=15629}
}