Dawes, I.W. and J. Mandelstam (1969). ... Demongeot J., M. Kaufman and R. Thomas (2000). Positive ... Thomas, R and R. D'Ari (1990) Biological feedback.
Acta Biotheoretica 49: 207-218, 2001. c 2001 Kluwer Academic Publishers. Printed in the Netherlands.