Schlegel, H.G. & Jannasch, H.W. 2006. Chapter 1.6. Prokaryotes and Their Habitats. In M. Dworkin, S. Falkow, E. Rosenberg, K.-H. Schleifer & E. Stackebrandt (eds.), The Prokaryotes (ed. 3) 1. Springer: 137-184. ≡