Diet studies of seabirds: a review and  recommendations

Barrett, R.T., Camphuysen, C.J., Anker-Nilssen, T., Furness, R.W., Garthe, S., Hüppop, O., Leopold, M.F., Montevecchi, W.A. & Veit, R.R. 2007. Diet studies of seabirds: a review and  recommendations. ICES Journal of Marine Science 64: 1675-1691.