Jelaskan Loon pasifik, Gavia pacifica dari Loon

Loon besar utara, Gavia immer

Loon paruh kuning, Gavia adamsii

Olson, Storrs L. (1985): Section X.I. Gaviiformes. In: Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): Avian Biology 8: 202–214. Academic Press, New York.