UK Department for the Environment, Food and Rural Affairs (2001): "Guidelines for Company Reporting on Greenhouse Gas Emissions", Londra, DEFRA Publications, Internet: www.defra.gov.uk/environment/envrp/ index.htm (Ministero britannico Ambiente, Prodotti alimentari e Affari rurali - Orientamenti per le relazioni delle imprese sulle emissioni di gas serra)
UK Department for the Environment, Food and Rural Affairs (2001): "Guidelines for Company Reporting on Greenhouse Gas Emissions", London, DEFRA Publications, Internet: www.defra.gov.uk/environment/envrp/ index.htm.