The ⊕ c -topology is not completable
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 10 (1983) no. 4, pp. 579-586. 
@article{ASNSP_1983_4_10_4_579_0,
     author = {Mader, Adolf},
     title = {The $\oplus _c$-topology is not completable},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {579--586},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 10},
     number = {4},
     year = {1983},
     zbl = {0537.20029},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1983_4_10_4_579_0/}
}
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Mader, Adolf. The $\oplus _c$-topology is not completable. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 4, Tome 10 (1983) no. 4, pp. 579-586. http://www.numdam.org/item/ASNSP_1983_4_10_4_579_0/

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