Canonical structural spine
The work's own structure
Reviewed edition: Ovid, Die Metamorphosen des P. Ovidius Naso, vols. 1-3, ed. Hugo Magnus, Gotha, F. A. Perthes, 1892. Division axes: book → 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.