Notes on verification

Confirmed by multiple independent sources including a Cambridge University Press scholarly work; the 12 Mark price applied to the paperback binding variant, with a 14 Mark hardcover variant also existing simultaneously. [tier=gold indep_score=0.838 clusters=4 claim_tier=notable | framework convergence=partial (upstreams: Bürgin bibliography of Thomas Mann's works, S. Fischer Verlag publication records) — publishers independent, evidence may not be | kind=empirical eligibility=high]