Liang's 2009 essay and Greenhalgh's 2003 article each independently contain both the June-1978-meeting fact and Song's 1978-Europe fact — the vault's first symmetric 'shared landlord' bridge in this cluster

chinapopulation-policyone-child-policyhistoriographycontested-causationcold-war-sciencegreenhalghliang-zhongtangsong-jianchen-muhuabridge-seed

A bridge-seed check investigated a high-cosine (0.87), previously unlinked pairing between claim-liang-2009-essay-corroborates-song-jian-1978-foreign-cybernetics-exposure and claim-greenhalgh-2003-article-independently-corroborates-june-1978-leading-group-meeting. Read in full, Liang Zhongtang's 2009 essay and Susan Greenhalgh's 2003 article each turn out to contain both of the two facts the two seed notes separately corroborate, not just the one each note cites. Liang's essay holds the June-1978 three-day meeting in its §一 (claim-liang-2009-dates-one-child-policy-origin-to-june-1978-three-day-meeting) and the "宋健說" account of Song Jian's foreign-cybernetics exposure a few pages later in §三 (claim-liang-2009-essay-corroborates-song-jian-1978-foreign-cybernetics-exposure). Greenhalgh's article holds the same June-1978 meeting at p. 185 (claim-greenhalgh-2003-article-independently-corroborates-june-1978-leading-group-meeting) and Song's 1978 Europe encounter fifteen pages earlier at p. 170 (claim-song-jian-1986-essay-quote-dates-cybernetics-exposure-to-1978). Neither historian cites the other for either fact — Liang names no Western source for the "宋健說" narrative, and Greenhalgh's citation for the June-1978 meeting is "Li 1980," not Liang.

This is the cluster's third resolved instance of the "shared landlord, not shared argument" shape a bridge-seed check produces — after observation-liang-2009-sentence-bridges-forrester-note-and-olsder-1975-note (one sentence of Liang's essay holding two other notes' claims) and claim-liang-causal-credit-and-song-self-report-notes-connect-only-through-greenhalgh-2003 (two other notes connected only through an unread passage of Greenhalgh's article) — but the first where the shared material sits in both documents rather than one: each historian's own text independently pairs the same two 1978 facts, because both are live data points in the credit dispute each is litigating from an opposite side.