1. Logical foundation of probability;Carnap,1951
2. J. Oš, Remarks on foundation of probability, Proc. 1962 Intern. Congress of Mathematicians, Stockholm (1963)
3. La prévision: ses lois logiques, ses sources subjectives;de Finetti;Ann. Inst. Henri Poincaré,1937
4. Algebraic logic;Halmos,1962
5. J. E. Fenstad, On representation of polyadic algebras, Kongelige Norske Vid. Selsk. Forh. (Trondheim 1964)