na INLIS000000000002593 Ind 0010-1118002593 Ecology and population dynamics of the common Eider in the Dutch wadden sea SWENNEN, Cornelis Cornelis Swennen Groningen University of Groningen 1991 143 p. : ill. ; 24 cm.-- 143 p. : ill. ; 24 cm.-- 598.412SWEe 598.412(492)_ DUCKS ANIMAL ECOLOGY POPULATION CHANGE NETHERLAND 189/92