1. Altman, E. (1999). Constrained Markov decision processes (Vol. 7). Boca Raton: CRC Press.
2. Arora, S., & Karakostas, G. (2000). A $2+\epsilon $ approximation algorithm for the k-MST problem. In Proceedings of the eleventh annual ACM-SIAM symposium on discrete algorithms (SODA-2000) (pp. 754–759).
3. Åström, K. J. (1965). Optimal control of Markov processes with incomplete state information. Journal of Mathematical Analysis and Applications, 10(1), 174–205.
4. Aumann, Y., Hazon, N., Kraus, S., & Sarne, D. (2008). Physical search problems applying economic search models. In Proceedings of the twenty-third AAAI conference on artificial intelligence (AAAI-2008) (pp. 9–16).
5. Balas, E. (1989). The prize collecting traveling salesman problem. Networks, 19, 621–636.