Canonical structural spine
The work's own structure
Reviewed edition: Cicero. De Officiis. Miller, Walter, editor. William Heinemann and G.P. Putnam's Sons, 1913. Division axes: book → section. 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.