1. Azam, F., B.B. Hemmingsen and B.E. Volcani: Role of silicon in diatom metabolism. Arch. Mikrobiol. 97, 103?114 (1974)
2. Bremer, H. and P.P. Dennis: Transition period following a nutritional shift-up in the bacterium Escherichia coli B/r: stable RNA and protein synthesis. J. theor. Biol. 52, 365?382 (1975)
3. Caperon, J. and J. Meyer: Nitrogen-limited growth of marine phytoplankton. Part II. Uptake kinetics and their role in nutrient limited growth of phytoplankton. Deep-Sea Res. 19, 619?632 (1972)
4. Cleland, W.: The statistical analysis of enzyme kinetic data. Adv. Enzymol. 29, 1?32 (1967)
5. Conway, H.L.: The uptake and assimilation of inorganic nitrogen by Skeletonema costatum (Grev.) Cleve, Ph.D. Dissertation, 125 pp. University of Washington, Seattle 1974