Two Russian-language tertiary mirrors attach Fel'dbaum's full 1945–1964 Dzerzhinsky range to teaching and name the same department, but only Cyclowiki dates the professorship 1945–1961

feldbaumcold-war-sciencemissile-scienceinstitutional-historyverificationsource-provenance

Russian Wikipedia and Cyclowiki (Циклопедия) both give a more specific version of Fel'dbaum's Dzerzhinsky Academy post than English Wikipedia's uncited "professor of missile control systems, 1945–1964" (claim-feldbaum-missile-control-systems-professorship-1945-1964-unverified). Both name the department directly — "профессор кафедры систем управления ракет факультета реактивного вооружения," professor of the Department of Rocket Control Systems, Faculty of Reactive Armament — and both attach the full 1945–1964 range to general teaching of courses (electrical engineering, radio engineering, automatic-control theory, and others) rather than to the professorship. On the professorship's own dates the two mirrors diverge: Cyclowiki dates it 1945–1961, while Russian Wikipedia only start-dates it ("С 1945 года") with no end year — and Cyclowiki separately records the professor title as conferred in 1954, an internal tension it does not resolve. 1961 is independently the year every source agrees Fel'dbaum became head of the Laboratory of Self-Adjusting Systems at the Institute of Automation and Telemechanics — so on Cyclowiki's dating he kept teaching at the military academy for three years after his formal title and primary institutional home had already moved.

This narrows the vault's existing unverified claim without confirming it: the specific pairing of "1945–1964" with a professorship does not survive contact with either Russian source, which instead attach that full range only to teaching activity broadly. A named institutional detail, the Dzerzhinsky Academy's own Faculty of Reactive Armament, is independently dated to founding in 1945 by a third, Tier 3 source (claim-dzerzhinsky-artillery-academy-institutional-ancestor-peter-the-great-missile-academy) — the same year Fel'dbaum's tenure is said to begin, though that source does not name him.

[unverified-mechanism -- needs Tier 1-2 primary]. Neither mirror is itself a primary source, and per the vault's sourcing floor a surprising, load-bearing biographical claim like a specific department title needs Tier 1–2 corroboration it does not yet have.