http://mathworld.i2p/BaersCriterion.html
Amer. Math. Soc. 46 , 800-806, 1940. Faith, C. Algebra: Rings, Modules and Categories, I. Berlin, p. 157, 1973. Lam, T. Y. Lectures on Modules and Rings. New York: Springer-Verlag, p. 63, 1999. Referenced on Wolfram|Alpha Baer's Criterion Cite this as: Barile, Margherita . " Baer's Criterion. " From MathWorld --A Wolfram Web Resource, created by Eric W.