Luc Bouten Ramon van Handel Matthew R. James An Introduction to Quantum Filtering. 2199-2241 2007 46 SIAM J. Control. Optim. 6 https://doi.org/10.1137/060651239 https://www.wikidata.org/entity/Q29010625 db/journals/siamco/siamco46.html#BoutenHJ07