A tomographic setting for quasi-distribution functions
  The method of constructing the tomographic probability distributions describing quantum states in parallel with density operators is presented. Known examples of Husimi-Kano quasi-distribution and photon number tomography are reconsidered in the new setting. New tomographic schemes based on coherent states and nonlinear coherent states of deformed oscillators, including q-oscillators, are suggested. The associated identity decompositions providing Gram-Schmidt operators are explicitly given, and contact with the Agarwal-Wolf $\Omega$-operator ordering theory is made. 
V.I. Man'ko, G. Marmo, A. Simoni, E.C.G. Sudarshan, F. Ventriglia