Relativistic free-particle quantization on the light-front: New aspects
  We use the light-front machinery to study the behavior of a relativistic free particle and obtain the quantum commutation relations from the classical Poisson brackets. We argue that the usual projection onto the light-front coordinates for these from the covariant commutation ralations does not reproduce the expected results. 
J. H. O. Sales, A. T. Suzuki and G.E.R. Zambrano