1. H.H. Boswinkel, Scheepsvoortstuwing met brandstofcellen [Ship propulsion with fuel cells], ECN-C-91-022, 1992, 39 pp.
2. NN, Replacing Iceland's Fossil Fuels, Fuel Cell Technology News, Vol. 1, No. 6, 1999, p. 3.
3. G. Sattler, Wasserstoffantriebe für Überwasserschiffe [Hydrogen propulsion systems for surface vessels], Sea 2000 Proceedings Hamburg, 1996, pp. 161–169.
4. C. Eusterbarkey, et al., Solare Wasserstoff-Technologie der Zukunft [Solar hydrogen technology of the future], Signet-Verlag, Flensburg, 1998.
5. NN, Passagierschiffe mit PEM-Brennstoffzelle [Passenger ships using PEM fuel cells], Hyweb, http://www.wasserstoff.de, 1998.