Canonical structural spine
The work's own structure
Reviewed edition: P. Ovidius Naso, vol. 1, ed. Rudolf Ehwald, Leipzig: B. G. Teubner, 1907. Division axes: epistle → 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.