Buhari I · Babangida (1983–1993)

Tiv-Jukun conflicts (recurring since 1992); Fulani-farmer violence (acute, 2010–present); Mambilla plateau crisis

Methodology

Tier 1 · primary

Courts. Gazettes. National archives.

Tier 2 · corroborating

OCCRP. HRW. BudgIT. TheCable.

Tier 4 · tertiary, flagged

Wikipedia only where primary is pending. Always labelled.