John M. Bownds, J. M. Cushing On Preserving Stability of Volterra Integral Equations under a General Class of Perturbations. [Citation Graph (0, 0)][DBLP] Mathematical Systems Theory, 1975, v:9, n:2, pp:117-131 [Journal]
J. M. Cushing Strong Stability of Perturbed Systems of Volterra Integral Equations. [Citation Graph (0, 0)][DBLP] Mathematical Systems Theory, 1974, v:7, n:4, pp:360-366 [Journal]