<ref name=":7">Baum L E and Petrie T. Statistical inference for probabilistic functions of finite state Markov chains. The annals of mathematical statistics, 1966, 37(6): 1554-1563.</ref>。 | <ref name=":7">Baum L E and Petrie T. Statistical inference for probabilistic functions of finite state Markov chains. The annals of mathematical statistics, 1966, 37(6): 1554-1563.</ref>。 |