Canonical structural spine
The work's own structure
Reviewed edition: Horace. The Works of Horace. Vol. II. Smart, Christopher, editor. Philadelphia: J. Whetham, 1836. Division axes: book → poem → line. Structural nodes alone do not assert commentary citations.
Record-local commentary evidence
Commentary citations: work locus ↔ Dante locus
These citations occur in later commentary. They do not, by themselves, mean Dante cited this work.