• [1] R. Bott and H. Samelson, On the Pontryagin product in spaces of paths, Comment. Math. Helv. 27 (1953), 320–337 (1954). MR 0060233, https://doi.org/10.1007/BF02564566
• [2] B. Eckmann and P. J. Hilton, Group-like structures in general categories. I, Math. Ann. 145 (1962), 227-255; II, ibid. 151 (1963), 150-186; III, ibid. 150 (1963), 165-187.
• [3] B. Eckmann and P. J. Hilton, Structure maps in group theory, Fund. Math. 50 (1961/1962), 207–221. MR 0132776, https://doi.org/10.4064/fm-50-2-207-221
• [4] Daniel M. Kan, On monoids and their dual, Bol. Soc. Mat. Mexicana (2) 3 (1958), 52–61. MR 0111035
• [5] Daniel M. Kan, A combinatorial definition of homotopy groups, Ann. of Math. (2) 67 (1958), 282–312. MR 0111032, https://doi.org/10.2307/1970006

Bibliography

[1]

R. Bott and H. Samelson, On the Pontryagin product in spaces of paths, Comment. Math. Helv. 27 (1953), 320-337. MR 0060233 (15:643b)

[2]

B. Eckmann and P. J. Hilton, Group-like structures in general categories. I, Math. Ann. 145 (1962), 227-255; II, ibid. 151 (1963), 150-186; III, ibid. 150 (1963), 165-187.

[3]

-, Structure maps in group theory, Fund. Math. 50 (1961/62), 207-221. MR 0132776 (24:A2612)

[4]

D. M. Kan, On monoids and their dual, Bol. Soc. Mat. Mexicana (2) 3 (1958), 52-61. MR 0111035 (22:1900)

[5]

-, A combinatorial definition of homotopy groups, Ann. of Math (2) 67 (1958), 282-312. MR 0111032 (22:1897)