  I give an efficient algorithm for the reduction of multi-leg one-loop
integrals of rank one. The method combines the basic ideas of the spinor
algebra approach with the dual vector approach and is applicable to box
integrals or higher point integrals, if at least one external leg is massless.
This method does not introduce Gram determinants in the denominator. It
completes an algorithm recently given by R. Pittau.
