Controlled trial of azathioprine in children with nephrotic syndrome - Abramowicz, M; Barnett, H. L; Edelman, C. M, Jr.; Grtjfer, I; Kabazashi, O; Arneil, G. C; Barron, B. A; Gordillo, P. G; Hallman, N; Tiddens, H. A (Lancet, 1970)