• [1] Sammuel Eilenberg, Topological methods in abstract algebra. Cohomology theory of groups, Bull. Amer. Math. Soc. 55 (1949), 3–37. MR 0030523 (11,8b), http://dx.doi.org/10.1090/S0002-9904-1949-09161-9
• [2] Samuel Eilenberg and Saunders MacLane, General theory of natural equivalences, Trans. Amer. Math. Soc. 58 (1945), 231–294. MR 0013131 (7,109d), http://dx.doi.org/10.1090/S0002-9947-1945-0013131-6
• [3] Samuel Eilenberg and Saunders MacLane, Cohomology theory of Abelian groups and homotopy theory. I, Proc. Nat. Acad. Sci. U. S. A. 36 (1950), 443–447. MR 0038072 (12,350c)
• [4] Roger Lyndon, New proof for a theorem of Eilenberg and MacLane, Ann. of Math. (2) 50 (1949), 731–735. MR 0030524 (11,8c)

Bibliography

[1]

Samuel Eilenberg, Topological methods in abstract algebra, cohomology theory of groups, Bull. Amer. Math. Soc. vol. 55 (1949) pp. 3-37. MR 0030523 (11:8b)

[2]

Samuel Eilenberg and Saunders MacLane, General theory of natural equivalences, Trans. Amer. Math. Soc. vol. 58 (1945) pp. 231-294. MR 0013131 (7:109d)

[3]

-, Cohomology theory of abelian groups and homotopy theory. I and II, Proc. Nat. Acad. Sci. U.S.A. vol. 36 (1950) pp. 443-447 and 657-663. MR 0038072 (12:350c)

[4]

Roger Lyndon, New proof for a theorem of Eilenberg and MacLane, Ann. of Math. vol. 50 (1949) pp. 731-735. MR 0030524 (11:8c)