[116] Bach, H., Christensen, N. Kristensen, P (Red.) 2002: The State of the Environment in Denmark, 2001, NERI Technical Report N° 409, Roskilde: National Environmental Research Institute, blz. 102. Zie ook: Danish Government, 2002: Denmark's National Strategy for Sustainable Development "A Shared Future - Balanced Development", Indicator Report, Kopenhagen: Danish Environmental Protection Agency, blz. 47.
[116] Bach, H., Christensen, N. Kristensen, P (Hrsg.) National Environmental Research Institute: The State of the Environment in Denmark, 2001, NERI Technical Report Nr. 409, S. 102, Roskilde 2002. S. a. Dänische Regierung/Dänische Umweltschutzbehörde: Denmark's National Strategy for Sustainable Development "A Shared Future - Balanced Development", Indicator Report, S. 47. Kopenhagen 2002.