DS-39
DS-39 is a medium machine gun or weapon model.
Overview
USSR machine gun.
In detail
It is associated with Soviet Union. The record gives 1930 as its date of establishment or first appearance.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“DS-39”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1182924: DS-39
Consult the source