[1] W. Banaszczyk: 
Additive Subgroups of Topological Vector Spaces. Lecture Notes in Mathematics 1466. Springer-Verlag, Berlin-Heidelberg-New York, 1991. 
MR 1119302 
[2] E. Binz: 
Continuous Convergence in $C(X)$. Lecture Notes in Mathematics 469. Springer-Verlag, Berlin-Heidelberg-New York, 1975. 
MR 0461418 
[3] R. Brown, P. J. Higgins and S. A. Morris: 
Countable products and sums of lines and circles: their closed subgroups, quotients and duality properties. Math. Proc. Camb. Phil. Soc. 78 (1975), 19–32. 
DOI 10.1017/S0305004100051483 | 
MR 0453915 
[4] H. P. Butzmann: 
Pontryagin duality for convergence groups of unimodular continuous functions. Czechoslovak Math. J. 33 (1983), 212–220. 
MR 0699022 | 
Zbl 0528.54005 
[5] H. P. Butzmann: $c$-Duality Theory for Convergence Groups. Lecture in the Course “Convergence and Topology”. Erice, 1998.
[10] S. Kaplan: 
Extensions of the Pontryagin duality I: Infinite products. B. G. Duke Math. 15 (1948), 649–658. 
MR 0026999 
[11] H. Leptin: 
Bemerkung zu einem Satz von S. Kaplan. B. G.  Arch. der Math. 6 (1955), 264–268. 
MR 0066397 | 
Zbl 0065.01601 
[12] E. Martín-Peinador: 
A reflexive admissible topological group must be locally compact. Proc. Amer. Math. Soc. 123 (1995), 3563–3566. 
DOI 10.2307/2161108 | 
MR 1301516 
[14] N. Roelcke and S. Dierolf: 
Uniform Structures on Topological Groups and Their Quotients. Advanced Book Program. McGraw-Hill International Book Company, 1981. 
MR 0644485