1. R. C. Braithwaite: The Nature of theoretical Concepts and the Role of Models in an advanced Science (Revue Internationale de Philosophie, 1954, fasc. 1–2).
2. M. B. Hesse: Models in Physics (British Journal for the Philosophy of Science, 1954, pp. 198–214). E. H. Hutten: The role of Models in Physics (BJPS, 1954, pp. 284–301 ).
3. Rudolf Carnap: Introduction to Semantics, Harvard University Press, 1946.
4. John G. Kemeny: A New Approach to Semantics, Part I (Journal for Symbolic Logic, 1956 ).
5. For information about dimensional analysis, consult N. R. Campbell: Foundations of Science (ch. XIV and XV) and P. W. Bridgman: Dimensional Analysis.