Distributori per gas metano e G.P.L. in Europa
www.gas-tankstellen.info
Unione europea delle industrie a Gas Naturale
www.eurogas.org
Associazione inglese per il G.P.L.
www.boostlpg.co.uk
Associazione mondiale GPL
www.worldlpgas.com
Association des Gaz de petroles liquefies
www.aegpl.com
World LP Gas Association
www.worldlpg.com
Periodico Latinoamericano del Gas Vehicular
www.prensavehicular.com
Vertical Portal on Alternative Fuels
www.alternativefuelvehicles.com
International Energy Agency
www.iea.org