Weyl-Underhill-Emmrich quantization and the Stratonovich-Weyl quantizer
  Weyl-Underhill-Emmrich (WUE) quantization and its generalization are considered. It is shown that an axiomatic definition of the Stratonovich-Weyl (SW) quantizer leads to severe difficulties. Quantization on the cylinder within the WUE formalism is discussed. 
J. Plebanski, M. Przanowski and F.J. Turrubiates