  Within unbroken SUSYQM and for zero factorization energy, I present an
iterative generalization of Mielnik's isospectral method by employing a
Schroedinger true zero mode in the first-step general Riccati solution and
imposing the physical condition of normalization at each iterative step. This
procedure leads to a well-defined multiple-parameter structure within Mielnik's
construction for both zero modes and potentials
