1. Barker, S., 1961, ?On Simplicity in Empirical Hypotheses?, Philosophy of Science 28, 162?71.
2. Black, M., 1954, Problems of Analysis, Cornell University Press, Ithaca N.Y., Ch. X.
3. Black, M., 1962, Models and Metaphors, Cornell University Press, Ithaca N.Y., Ch. XI.
4. Carnap, R., 1950, The Logical Foundations of Probability, University of Chicago Press, Chicago.
5. Carnap, R., 1952, The Continuum of Inductive Methods, University of Chicago Press, Chicago.