TMD PDFs: a Monte Carlo implementation for the sea quark distribution
  This article gives an introduction to transverse momentum dependent (TMD) parton distribution functions and their use in shower Monte Carlo event generators for high-energy hadron collisions, and describes recent progress in the treatment of sea quark effects within a TMD parton-shower framework. 
F. Hautmann, M. Hentschinski and H. Jung
hep-ph