Symplectic Quantization of Massive Bosonic string in background B-field
  We give the details of symplectic quantization for a system containing second class constraints. This method is appropriate for imposing infinite series of constraints due to the boundary conditions. We use this method for massive bosonic strings in a background B-field and find the correct expansions of the fields in terms of the physical modes. We have found a canonical basis for this model. 
A. Shirzad, A. Bakhshi and Y. Koohsarian
hep-th