On the linear forms of the Schrodinger equation
  Generalizing the linearisation procedure used by Dirac and later by L\'evy-Leblond, we derive the first-order non-relativistic wave equations for particles of spin 1 and spin 3/2 starting from the Schrodinger equation. 
Y. Kasri, A. B\'erard, Y. Grandati and L. Chetouani
quant-ph math-ph math.MP