• [1] Reinhold Baer, Das Hyperzentrum einer Gruppe. III, Math. Z. 59 (1953), 299–338 (German). MR 0059906, https://doi.org/10.1007/BF01180263
• [2] P. Hall, A contribution to the theory of groups of prime power order, Proc. London Math. Soc. (2) vol. 36 (1933) pp. 29-95.
• [3] K. A. Hirsch, On infinite soluble groups II, ibid. vol. 44 (1938) pp. 336-344.
• [4] K. A. Hirsch, On infinite soluble groups. III, Proc. London Math. Soc. (2) 49 (1946), 184–194. MR 0017281, https://doi.org/10.1112/plms/s2-49.3.184

Bibliography

[1]

Reinhold Baer, Das Hyperzentrum einer Gruppe III, Math. Zeit. vol. 59 (1953) pp. 299-338. MR 0059906 (15:598g)

[2]

P. Hall, A contribution to the theory of groups of prime power order, Proc. London Math. Soc. (2) vol. 36 (1933) pp. 29-95.

[3]

K. A. Hirsch, On infinite soluble groups II, ibid. vol. 44 (1938) pp. 336-344.

[4]

-, On infinite soluble groups III, ibid. vol. 49 (1945-47) pp. 184-194. MR 0017281 (8:132a)