An Introduction to Quantum Filtering, L. Bouten, R. Van Handel and M. R. James,
SIAM Journal on Control and Optimization, 46, 2199 (2007). Free access on arxiv.org.
A Discrete Invitation to Quantum Filtering and Feedback Control,
L. Bouten, R. Van Handel and M. R. James, SIAM Review, 51, 239 (2009). Free access on arxiv.org.