SK1 of finite abelian groups. I. M.R. Stein; R.C. Alperin; R.K. Dennis — 1985 Inventiones mathematicae
On the Schur Multipliers of Steinberg and Chevalley Groups over Commutative Rings. Wilberd van der Kallen; M.R. Stein — 1977 Mathematische Zeitschrift