Redigerer Nebb (avsnitt)

== Referanser ==
<references>
<ref name="Bonser & Witter (1993)">Bonser RH; Mark S Witter (1993). Indentation hardness of the bill keratin of the European Starling. ''The Condor'' '''95''':736–738. doi:[https://doi.org/10.2307/1369622 10.2307/1369622]</ref>

<ref name="Gill (1995)">Gill, Frank B. (1995). ''Ornithology'' (2). New York, NY: W. H. Freeman and Company. ISBN 0-7167-2415-4.</ref>

<ref name="Hieronymus & Witmer (2010)">Hieronymus, Tobin L.; Witmer, Lawrence M. (2010). ”Homology and Evolution of Avian Compound Rhamphothecae”. ''The Auk'' '''127'''(3):590–604. doi:[https://doi.org/10.1525/auk.2010.09122 10.1525/auk.2010.09122]</ref>

<ref name="Klasing (1999)">Klasing, Kirk C. (1999). ”Avian gastrointestinal anatomy and physiology”. ''Seminars in Avian and Exotic Pet Medicine'' '''8''' (2): sid. 42–50. doi:[https://doi.org/10.1016/S1055-937X(99)80036-X 0.1016/S1055-937X(99)80036-X]</ref>

<ref name="Miserez, Waite & Zok (2007)">Miserez, A., Y. Li, J.H. Waite & F. Zok (2007). "Jumbo squid beaks: Inspiration for design of robust organic composites" (PDF). ''Acta Biomaterialia'' '''3'''(1): 139–149. doi:[https://doi.org/10.1016/j.actbio.2006.09.004 10.1016/j.actbio.2006.09.004]</ref>

<ref name="Pitocchelli, Piatt & Carter (2003)">Pitocchelli, Jay; John F. Piatt; Harry R. Carter (2003). ”Variation in plumage, molt, and morphology of the Whiskered Auklet (''Aethia pygmaea'') in Alaska”. ''Journal of Field Ornithology'' '''74''' (1): sid. 90–98. doi:[https://doi.org/10.1648/0273-8570-74.1.90 10.1648/0273-8570-74.1.90]</ref>

<ref name="Proctor & Lynch (1998)">Proctor, Noble S.; Lynch, Patrick J. (1998). ''Manual of Ornithology: Avian Structure and Function''. New Haven, CT: Yale University Press. ISBN 0-300-07619-3.</ref>
</references>