R.R. Andruszkiewicz and M. Woronowicz, On associative ring multiplication on abelian mixed groups, Comm. Algebra 42 (2014), no. 9, 3760–3767.
Google Scholar

R.R. Andruszkiewicz and M. Woronowicz, On SI-groups, Bull. Aust. Math. Soc. 91 (2015), no. 1, 92–103.
Google Scholar

R.R. Andruszkiewicz and M. Woronowicz, The classification of torsion-free TI-groups, Algebra Colloq. 29 (2022), no. 4, 595–606.
Google Scholar

R.A. Beaumont, Rings with additive group is the direct sum of cyclic groups, Duke Math. J. 15 (1948), 367–369.
Google Scholar

S. Breaz and G. Călugăreanu, Additive groups of rings with identity. Avaliable at http://math.ubbcluj.ro/~calu/ident.pdf.
Google Scholar

S. Feigelstock, Additive Groups of Rings, Vol. I, Res. Notes in Math., 83, Pitman (Advanced Publishing Program), Boston, MA, 1983.
Google Scholar

S. Feigelstock, Additive Groups of Rings, Vol. II, Pitman Res. Notes Math. Ser., 169, Longman Scientific & Technical, London, 1988.
Google Scholar

S. Feigelstock, Additive groups of rings whose subrings are ideals, Bull. Austral. Math. Soc. 55 (1997), no. 3, 477–481.
Google Scholar

L. Fuchs, Infinite Abelian Groups, Vol. I, Pure Appl. Math., Vol. 36, Academic Press, New York-London, 1970.
Google Scholar

L. Fuchs, Infinite Abelian Groups, Vol. II, Pure Appl. Math., Vol. 36-II, Academic Press, New York-London, 1973.
Google Scholar

F. Hasani, F. Karimi, A. Najafizadeh, and Y. Sadeghi, On the square subgroups of decomposable torsion-free abelian groups of rank three, Adv. Pure Appl. Math. 7 (2016), no. 4, 259–265.
Google Scholar

E.I. Kompantseva, Abelian dqt-groups and rings on them (in Russian), Fundam. Prikl. Mat. 18 (2013), no. 3, 53–67; translation in J. Math. Sci. (N.Y.) 206 (2015), no. 5, 494–504.
Google Scholar

E.I. Kompantseva and T.Q.T. Nguyen, Algebraically compact abelian TI-groups (in Russian), Chebyshevski ̆ı Sb. 20 (2019), no. 1, 204–213.
Google Scholar

P.T.T. Thuy, Torsion Abelian RAI-groups (in Russian), Fundam. Prikl. Mat. 17 (2012), no. 8, 109–138; translation in J. Math. Sci. (N.Y.) 197 (2014), no. 5, 658–678.
Google Scholar

M. Woronowicz, A note on the square subgroups of decomposable torsion-free abelian groups of rank three, Ann. Math. Sil. 32 (2018), no. 1, 319–331.
Google Scholar

M. Woronowicz, A note on Feigelstock’s conjecture on the equivalence of the notions of nil and associative nil groups in the context of additive groups of rings of finite rank, Bull. Belg. Math. Soc. Simon Stevin 27 (2020), no. 4, 509–519.
Google Scholar