Distribution studies of waders and shelduck on the Severn Estuary with reference to sediment mobility /
Warbrick, Susan.
Clark, Nigel A.
Donald, Paul F.
British Trust for Ornithology.
Thetford : British Trust for Ornithology,
1994.
"October 1991."
Report to the Severn Tidal Power Group under contract to Balfour Beatty Ltd.