एपीए उद्धरण

COWI Consulting Engineers and Planners AS. (1999). Economic instruments in environmental protection in Denmark. Denmark: Ministry of Environment and Energy.

शिकागो स्टाइल उद्धरण

COWI Consulting Engineers and Planners AS. Economic Instruments in Environmental Protection in Denmark. Denmark: Ministry of Environment and Energy, 1999.

एमएलए उद्धरण

COWI Consulting Engineers and Planners AS. Economic Instruments in Environmental Protection in Denmark. Denmark: Ministry of Environment and Energy, 1999.