NICHOLSON, K. & HEIN, J.R. & BHHN, B. & DASGUPTA, S. (1996):
Manganese Mineralization: Geochemistry and Mineralogy of Terrestrial and Marine Deposits. 352 S., sehr viele Abb.,
[Precambrian to modern manganese mineralization. More than 20 papers about occurence, origin, mineralogy and geochemistry, a.o. the ferromanganese concretions of the Baltic Sea.]