Woehler E.J., Cooper J., Croxall J.P., Fraser W.R., Kooyman G.L., Miller G.D., Nel D.C., Patterson D.L., Peter H.U., Ribic C.A., Salwicka K., Trivelpiece W.Z. & Weimerskirch H. (2001). A statistical assessment of the status and trends of Antarctic and Subantarctic seabirds..