1. Council of the European Union, 1999, Council Directive 1999/31/EC on the landfill of waste, Retrieved 18th of April, 2015, from: http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:31999L0031.
2. European Parliament 2, 2000, Directive 2000/76/EC on the Incineration of Waste, Retrieved 18th of April, 2015, from: http://www.central2013. eu/fileadmin/user_upload/Downloads/Document_Centre/OP_Resources/Incineration_Directive_2000_76. pdf.
3. NIST 1, 2000, NIST X-ray Photoelectron Spectroscopy Database, Retrieved 24th of November, 2015, from: http://srdata.nist.gov/xps/XPSDetailPage.aspx?AllDataNo=276.
4. NIST 2, 2000, NIST X-ray Photoelectron Spectroscopy Database, Retrieved 24th of November, 2015, from: http://srdata.nist.gov/xps/XPSDetailPage.aspx?AllDataNo=111111.
5. NIST 3, 2000, NIST X-ray Photoelectron Spectroscopy Database. Retrieved 24th of November, 2015, from: http://srdata.nist.gov/xps/EngElmSrchQuery.aspx?EType=PE&CSOpt=Retri_ex_dat&Elm=Si.