[11] EMA, 2002: Environmental Signals 2002 - Benchmarking the millennium, Environmental assess ment report N. 9, Kopenhagen: Europees Milieuagentschap, hoofdstuk 12, blz. 100-105.
[11] EUA, 2002: Environmental Signals 2002 - Benchmarking the millennium, Environmental assessment report N. 9, Copenhagen: European Environment Agency, Kapitel 12, S.. 100-105.