1. Directive 98/70/EC of the European Parliament and of the Council http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31998L0070:EN:HTML.
2. Directive 2003/17/EC of the European Parliament and of the Council http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:076:0010:0019:EN:PDF.
3. Directive 2009/30/EC of the European Parliament and of the Council http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:140:0088:0113:EN:PDF.
4. Economics of upgrading Fischer-Tropsch products;Shah,1990
5. Reforming – industrial. encyclopedia of catalysis;Moser,2007