Mitchell, P.I., Newton S.F., Ratcliffe, N. & Dunn T.E. (2004) "Seabird Populations of Britain and Ireland" T. & A.D. Poyser, London [notes] Page at Bloomsbury Publishing
Parsons, M. (2004) "Mediterranean Gull (Larus melanocephalus)" in Mitchell, P.I. et al. (2004) [notes]
