Whooper swan : cygnus cygnus  : (Iceland population) in Britain and Ireland 1960/61-1999/2000 /
Robinson, James A.(James Alexander),1973-
Joint Nature Conservation Committee (Great Britain)
Wildfowl & Wetlands Trust.
Slimbridge : WWT ; Peterborough : Joint Nature Conservation Committee,
[2004].
Includes bibliographical references.
Whooper swan
Bird surveys