Olsder's 1975 Twente-contact account is itself a retrospective reconstruction, assembled 33 years later after Olsder learned Susan Greenhalgh's book named him

chinapopulation-policyone-child-policyhistoriographycold-war-sciencenetherlandsoral-historyself-attributionunverified

Olsder's account of the 1975 Twente conversation is not a memory volunteered on its own initiative. The same U-Today article states that in 2008 — 33 years after the event — Geert Jan Olsder was approached by a journalist from the Dutch newspaper Trouw because Susan Greenhalgh's book Just One Child (2008) named both Olsder and Huibert Kwakernaak "a number of times." Olsder's own words describe the realization as retrospective and prompted: "It was only then that I realised that Jian had started working with my model, which I told him about in the Bastille in 1975. Everything fell into place." On his own telling, then, the connection between the 1975 Twente conversation and the one-child policy was not drawn until 2008, and was drawn under external prompting rather than volunteered beforehand. The earliest account of that connection held by this vault is later still — the 2024 U-Today interview quoted here. Whether the 2008 Trouw approach produced a published article has not been checked, and no 2008 text has been located or read by any vault session.

Just One Child (2008) is a distinct Greenhalgh publication from the 2005 China Quarterly paper the vault currently cites for Song's own self-credit quote (via claim-song-jian-self-credited-1980-projections-triggered-one-child-policy); the two are not yet distinguished as separate sources in the vault's frontmatter, and Just One Child itself remains unread by any session. This places Olsder's 1975 account and Song's own self-credit narrative on a structurally similar evidentiary footing regardless of their differing causal postures (see claim-olsder-declines-causal-credit-contrasts-song-jian-self-credit): both are decades-later personal accounts of proximity to the one-child policy's origin, recovered or amplified via exposure to Greenhalgh's published work rather than surfaced independently of it.