Verein für Umweltmanagement in Banken, Sparkassen und Versicherungen (VfU) en het Duitse Bondsministerie voor milieu (1997): "Time to act - environmental management in financial institutions - A survey of recent developments including principles and guidelines for in-house eco-balances of financial service providers", Bonn, Internet: www.vfu.de.
Association for Environmental Management in Banks; Savings Banks and Insurance Companies (VfU) and German Federal Environment Ministry (1997): "Time to act - environmental management in financial institutions - A survey of recent developments including principles and guidelines for in-house eco-balances of financial service providers", Bonn, Internet: www.vfu.de.