Lc. Sun, GROWTH OF BETTI NUMBERS OF MODULES OVER LOCAL-RINGS OF SMALL EMBEDDING CODIMENSION OR SMALL LINKAGE NUMBER, Journal of pure and applied algebra, 96(1), 1994, pp. 57-71
In this paper, we show that for modules over the local rings described
in the title, if the radius of convergence of the Poincare series is
less than one, then the Betti sequence is eventually nondecreasing and
has strong exponential growth.