1. Bogacz A., Buszman, E. & Wilczok, T. (1989): Competition between metal ions for dopa-melanin Stud. Biophys. 132: 189–195.
2. Bonser, R.H.C. (1997): Melanin and the abrasion resistance of feathers. Condor 590–591.
3. Borovansky, J., Horcicko, J. & Ducho, J. (1976): The hair melanosome: another tissue reservoir of zinc Physiol. bohemoslov. 25: 87–91.
4. Bowness, J.M., Morton, R.A., Shakir, M.H. & Stubbs, A.L. (1952): Distribution of copper and zinc in mammalian eyes. Occurence of metals in melanin fractions from eye tissues. Biochem. J. 51: 521–530.
5. Burger, J. (1994): Metals in avian feathers: Bioindicators of environmental pollution. Rev. Environ. Toxicol. 5: 197–306.