1. Chow, Y. S., Robbins, H., Siegmund, D. The Theory of Optimal Stopping. Corrected reprint of the 1971 original. Dover Publications, Inc., New York, 1991.
2. Dellacherie, C., Meyer, P.-A. Probabilités et Potentiel. Chapitres V a VIII. Théorie des Martingales. Revised edition. Actualités Scientifiques et Industrielles, 1385, Herman, Paris, 1980; English translation: Probabilities and potential. B. Theory of martingales. North-Holland Mathematics Studies, 72. North-Holland Publishing Co., Amsterdam, 1982.
3. Dubins, L. E., Shepp, L. A., Shiryaev, A. N. Optimal stopping rules and maximal inequalities for Bessel processes. (Russian) Teor. Veroyatnost. i Primenen.
38 (1993), no. 2, 288–330; translation in Theory Probab. Appl.
38 (1993), no. 2, 226–261.
4. Dynkin, E. B. Some limit theorems for sums of independent random quantities with infinite mathematical expectations. (Russian) Izv. Akad. Nauk SSSR. Ser. Mat. 19 (1955), 247-266
5. translation in Select. Transl. Math. Statist. and Probability, Vol. 1 (1961), pp. 171-189 Inst. Math. Statist. and Amer. Math. Soc., Providence, R.I.