@TechReport{barber05,
  author =	 {D. Barber and B. Mesot},
  title =	 {Construction and comparison of approximations for
                  switching linear {G}aussian state space models},
  institution =	 {IDIAP Research Institute},
  year =	 {2005},
  number =	 {IDIAP-RR-05-06},
  month =	 {February},
}