1. R.K. Dennis, Surjective stability for the functor K2, to appear.
2. The functor K2: a survey of computations and problems;Dennis,1973
3. M.J. Dunwoody, K2(ZΠ) for Π a group of order two or three, J. London Math. Soc., to appear.
4. Introduction to algebraic K-theory;Milnor,1971
5. On the K2 of a free associative algebra;Silvester;Proc. London Math. Soc.,1973