1. Babaee, A., Mashayekhy, B., Mirebrahimi, H.: On Hawaiian groups of some topological spaces. Topol. Appl. 159(8), 2043–2051 (2012)
2. Babaee, A., Mashayekhy, B., Mirebrahimi, H., Torabi, H.: On a van Kampen theorem for Hawaiian groups. Topol. Appl. 241, 252262 (2018)
3. Babaee, A., Mashayekhy, B., Mirebrahimi, H., Torabi, H., Abdullahi Rashid, M., Pashaei, S.Z.: On topological homotopy groups and its relation to Hawaiian groups. Hacet. J. Math. Stat. 49(4), 1437–1449 (2020)
4. Balcerzyk, S.: On factor groups of some subgroups of a complete direct sum of infinite cyclic groups. Bull. Acad. Polon. Sci. Sér. Sci. Math. Astron. Phys. 7, 141–142 (1959)
5. Bogopolski, O., Zastrow, A.: The word problem for some uncountable groups given by countable words. Topol. Appl. 159, 569–586 (2012)