Klensin & Romberg's 1989 chapter is the sole traceable source of the vault's 1977 TSP-manual date, with no sourcing of its own

werbostsp-manualbibliographyverificationhistory-of-mlmyth-ledger

John C. Klensin and Roselyn M. Romberg, "Statistical data management requirements and the SQL standards — an evolving comparison," in Statistical and Scientific Database Management (SSDBM 1988 proceedings), Lecture Notes in Computer Science vol. 339 (Springer, 1989), pp. 19–38 — the chapter behind DOI 10.1007/BFb0027503 — gives its reference-list entry for the manual as: "Brode, J., P. Werbos, and E. Dunn, TSP in the Datatran Language, Cambridge, MA, USA: MIT Laboratory of Architecture and Planning, 1977." This is the entire textual basis for the 1977 date recorded in claim-werbos-tsp-manual-first-publication (reached there via CrossRef's structured-reference metadata for the same DOI — a bibliographic index, not an independent witness).

Klensin & Romberg give no further sourcing for the date or the publisher attribution: it is a bare reference-list line among roughly sixty others, with no indication of whether it came from their own copy, a library catalog, or a citation chain. Their own reference list elsewhere cites a different MIT Laboratory of Architecture and Planning manual dated 1975 ("The Consistent System, Janus Reference Manual," Cambridge, MA, 1975), showing the same lab issued dated manuals in that period — a same-lab, same-era comparandum, not evidence for this manual's date either way.

The vault's competing date, 1975, comes from Werbos's own repeated self-citation (claim-werbos-1988-tsp-manual-citation-dated-1975). Neither source is the manual itself; the question stays open at question-werbos-tsp-manual-year-1975-vs-1977.