1. Kopell, N., and Howard, L. N., Lectures on Mathematics in the Life Sciences, 7, (edit. by Levin, S. A.), 201–216 (American Mathematical Society, Providence, Rhode Island, 1974).
2. Steele, J. H., Coastal Upwelling Ecosystems Analysis Newsletter, 2 (4), 3–7 (1973); Nature, 248, 83 (1974).
3. Levin, S. A., Am. Nat., 108, 207–228 (1974).
4. Segel, L. A., and Jackson, J. L., J. theor. Biol., 37, 545–559 (1972).
5. Segel, L. A., and Levin, S. A., Top. stat. Mech. Biophys. Proc. AIP Conf., 27, (American Institute of Physics, in the press).