@article {MR2086177,
	title = {Asymptotic stability of the Wonham filter: ergodic and nonergodic signals},
	journal = {SIAM J. Control Optim.},
	volume = {43},
	number = {2},
	year = {2004},
	pages = {643{\textendash}669},
	issn = {0363-0129},
	doi = {10.1137/S0363012902416924},
	url = {https://doi.org/10.1137/S0363012902416924},
	author = {Baxendale, Peter and Chigansky, Pavel and Liptser, Robert}
}
