  Fundamental to much work in small-x QCD is a k_T-factorization formula.
Normal expectations in theoretical physics are that when such a result is used,
citations should be given to where the formula is justified. We demonstrate by
examining the chains of citations back from current work that violations of
this expectation are widespread, to the extent that following the citation
chains, we do not find a proof or other justification of the formula. This
shows a substantial deficit in the reproducibility of a phenomenologically
important area of research. Since the published formulae differ in
normalization, we test them by making a derivation in a simple model that obeys
the assumptions that are stated in the literature to be the basis of
k_T-factorization in the small-$x$ regime. We find that we disagree with two of
the standard normalizations.
