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2. Survival rates and breeding biology of Puffins on Skomer Island, Wales;Ashcroft;Ornis Scand.,1979
3. Birkhead , T.R. 1976 Breeding biology and survival of Guillemots (Uria aalge) D. Phil, thesis Oxford University
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5. Reproductive biology of Thick-billed Murres (Uria lomvia): an inter-colony comparison;Birkhead;Auk,1981