1. American Mathematical Society Colloquium Publications, Vol. XXV;Birkhoff, Garrett,1961
2. N. Bourbaki, Éléments de mathématique. Première partie. Les structures fondamentales de l’analyse, Paris, Hermann, 1939-1955.
3. Theory of capacities;Choquet, Gustave;Ann. Inst. Fourier (Grenoble),1953
4. A solution to a set of fundamental equations in Markov chains;Derman, C.;Proc. Amer. Math. Soc.,1954
5. \bysame, Some contributions to the theory of Markov chains, Thesis, and Technical Report No. 7, Columbia University, Department of Mathematical Statistics, 1955.