Bewick's Swan Cygnus columbianus bewickii (Northwest Europe 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 : Wildfowl & Wetlands Trust ; Peterborough : Joint Nature Conservation Committee,
2004.
Includes bibliographical references.