  Precise determinations of the strong coupling constant in hadronic collisions
demand sets of parton densities spanning a sufficiently wide range of values
for the QCD scale parameter Lambda. For such applications, we supplement the
recent GRV parametrization by five sets of dynamically generated parton
distributions for Lambda-values corresponding to alpha_{S}(M_{Z}^{2}) between
0.104 and 0.122. Present DIS data, including recent small-x HERA results, do
not appreciably discriminate between these sets.
