Reference
Jacob Gonzalez-Solis, Xavier Ruiz, Lluis Jover (1999/2000): Fisheries and daily activity cycles of Audouins Larus audouinii and Yellow-legged Gulls L.cachinnans breeding at the Chafarinas Islands (Moroccan coast) – Vogelwarte - Zeitschrift für Vogelkunde – 40_1999: 52 - 56.