Integrated and unintegrated PDFs and GPDs from effective two-body   light-cone wave functions
  We suggest a classification scheme for parton distribution models, clarify the geometrical origin of unintegrated parton distribution relations, which were observed in various models, present new model relations, and provide for a so-called "spherical" model the analogous constraints for generalized parton distributions. Our findings suggest that various classes of uPDF and GPD models can be obtained from effective two-body light-cone wave functions. 
Dae Sung Hwang and Dieter Mueller
hep-ph