1. Anonymous: Copper, Nickel, Cobalt Availability. Mining Journal, 293, 7529, 469–471, London (1979)
2. Boin, U.: Grenzen und Möglichkeiten des Meeresbergbaus für die Gewinnung mineralischer Rohstoffe am Beispel der Manganknollen. Erzmetall 32, 237–240 (1979)
3. Bonatti, E. and Nayudu, Y.R.: The origin of manganese nodules on the ocean floor. Am. J. Science 263, 17–39 (1965)
4. Burns, R.G. and Burns, V.M.: Mineralogy. In: Glasby, G.P. (ed.): Marine Manganese Deposits. pp. 185–248, Elsevier, Amsterdam, 1977.
5. Cronan, D.S.: Regional geochemistry of ferromanganese nodules in the World Ocean. In: Horn, D.R. (ed.): Ferromanganese Deposits on the Ocean Floor. N.S.F., Washington DC, 19–30 (1972)