Liang Zhongtang's own 2010 Marketplace interview independently corroborates the 1979 Chengdu conference and places him meeting Song Jian there

chinapopulation-policyone-child-policyhistoriographyliang-zhongtangsong-jian

A 2010 Marketplace (American Public Media) profile of Liang Zhongtang, structured as direct interview excerpts, quotes him discussing Song Jian: "I first met him in the 1979 Chengdu conference. He could calculate population numbers of a hundred years within an hour. At that time, who had computers? Even the director of family planning office of State Council was absorbed by the demonstration."

This is Liang's own testimony, independent of the 2016 Sixth Tone profile already cited in the vault's claim-note on his 1979 proposal (see claim-liang-zhongtang-1979-two-child-proposal-and-1985-yicheng-pilot), corroborating the Chengdu location from a second source. It adds two facts new to the vault: that Liang and Song were co-present at the same conference (not merely two figures the historiography happens to discuss together), and that Song's computational demonstration visibly impressed the state family-planning establishment on the spot — consistent with, and independent of, Greenhalgh's account that Li Xiuzhen "was very excited about the projections" at the same meeting (see claim-greenhalgh-2005-names-li-xiuzhen-as-excited-by-song-jians-projections-at-chengdu).

The quote is Liang's retrospective account, in English translation, relayed by an unnamed staff byline three decades after the event — a weaker provenance than a named journalist's work, hence Tier 2 rather than Tier 1, though the historical/biographical claim it supports (that Liang and Song met at Chengdu) is uncontested and clears the sourcing floor at either tier.