Statistical inference for 2-type doubly symmetric critical irreducible   continuous state and continuous time branching processes with immigration
  We study asymptotic behavior of conditional least squares estimators for 2-type doubly symmetric critical irreducible continuous state and continuous time branching processes with immigration based on discrete time (low frequency) observations. 
Matyas Barczy, Krist\'of K\"ormendi, Gyula Pap
math.ST math.PR stat.TH