Key points are not available for this paper at this time.
David A. Buchsbaum, David Eisenbud, Algebra Structures for Finite Free Resolutions, and Some Structure Theorems for Ideals of Codimension 3, American Journal of Mathematics, Vol. 99, No. 3 (Jun., 1977), pp. 447-485
Buchsbaum et al. (Wed,) studied this question.