Bounds on the entropy rate of binary hidden Markov processes Erik Ordentlich and Tsachy Weissman
Relations between Information and Estimation in the presence of Feedback Himanshu Asnani, Kartik Venkat, and Tsachy Weissman
Entropy of Hidden Markov Processes and Connections to Dynamical Systems Brian Marcus, Karl Petersen, and Tsachy Weissma