(1973). Water resources in England and Wales [peta]. London : HMSO.
Cita Chicago (17th ed.)Water Resources in England and Wales [peta]. London : HMSO, 1973.
Cita MLA (9th ed.)Water Resources in England and Wales [peta]. London : HMSO, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.