1. Data based on joint Eurostat/OECD Questionnaire of 2002/2003, www.europa.eu.int/comm/eurostat.
2. European Environment Outlook Rep. (EEA), Rep. No. 4/2005, www.eea.eu.int, European Environment Agency, Copenhagen, Denmark, 2005.
3. European Environment Information and Observation Network (EIONET), www.waste.eionet.eu.int/wastebase.
4. Handbuch der Mechanischen Verfahrenstechnik, Bd. 1, 1. Aufl.,2003