1. Arnon, D. J., Yoch, D. C.: Photosynthetic bacteria. In: Frontiers of biology, Vol. 33. The biology of nitrogen fixation (A. Quispel, ed.), pp. 168?201. Amsterdam, Oxford, New York: North-Holland, American Elsevier 1974
2. Clayton, R. K.: Photosynthesis and respiration in Rhodospirillum rubrum. Arch. Mikrobiol. 22, 180?194 (1955)
3. Anais de Microbiologia;E. G. Cohn,1962
4. Deutsche Einheitsverfahren zur Wasseruntersuchung, 3. Aufl. Weinheim/Bergstr.: Verlag Chemie 1960
5. Eimhjellen, K. E., Jensen, S. L.: Biosynthesis of carotenoids in Rhodopseudomonas gelatinosa. Biochim. Biophys. Acta 82, 21?40 (1963)