UK Department for the Environment, Food and Rural Affairs (2000): "Environmental Reporting Guidelines for Company Reporting on Water", London, DEFRA Publications, Internet: www.defra.gov.uk/environment/envrp/ index.htm.
UK Department for the Environment, Food and Rural Affairs (2000) (ministère britannique de l'environnement, de l'alimentation et des questions rurales): Environmental Reporting Guidelines for Company Reporting on Water, London, DEFRA Publications, Internet: www.defra.gov.uk/environment/envrp/ index.htm.