Herzig, P. M., Petersen, S., and Hannington, M. D., 2002, Technical requirements for exploration and mining of seafloor massive sulphide deposits and cobalt-rich ferromanganese crusts, in Polymetallic Massive Sulphides and Cobalt-rich Ferromanganese Crusts -- Status and Prospects: United Nations International Seabed Authority, Technical Study No. 2, pp. 90 - 100.
Herzig, P.M., Petersen, S., and Hannington, 2002, Technical requirements for exploration and mining of seafloor massive sulphide deposits and cobalt-rich ferromanganese crusts, in Polymetallic Massive Sulphides and Cobalt-rich Ferromanganese Crusts - Status and Prospects: U.N. International Seabed Authority, Technical Study No. 2, pp. 90-100.