The Effect of Positivity Constraints on Polarized Parton Densities
  The impact of positivity constraints on the polarized parton densities has been studied. Special attention has been paid to the role of positivity constraints in determining the polarized strange quark and gluon densities, which are not well determined from the present data on inclusive polarized DIS. 
Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov