1. Carnap, Rudolf 1950, Logical Foundations of Probability, University of Chicago Press.
2. Flegg, H. Graham 1972, Boolean Algebra, Transworld Publishers Ltd, London.
3. Gaines, B. R. 1976, ?Behaviour/Structure Transformations under Uncertainty?, International Journal of Man-Machine Studies 8, 337?365.
4. Gaines, Brian R. 1977, ?System Identification, Approximation and Complexity?, International Journal of General Systems 3, 145?174.
5. Goodman, Nelson 1966, The Structure of Appearance, Second edition, The Bobbs-Merrill Company Inc., Indianapolis/New York/Kansas City.