Jeffrey, S. W. 1974. Profiles of Photosynthetic Pigments in the Ocean using Thin Layer Chromatography. Mar. Biol. 26: 101-110. Jeffrey, S.W., and G.F. Humphrey. 1975. New Spectro- photometric Equation for Determining Chlorophylls a, b, c1, and c2 in Higher Plants, Algae, and Natural Phytoplankton. Biochem. Physiol. Pflanzen 167:191-194. Smith, Stephen V., William J. Kimmerer, Edward A. Laws, Richard E. Brock, and Ted W. Walsh, 1981. Kaneohe Bay Sewage Diversion Experiment: Perspectives on Ecosystem Responses to Nutritional Perturbation. Pacific Science. Volume 35, Number 4, October 1981. pp. 402.
Columns are self-evident.