The Text
This Constitution shall come into force on the 29th day of May, 1999.
Source · Constitution of the Federal Republic of Nigeria, 1999, as amended · §320
All sections in Chapter VIII — Federal Capital Territory, General Supplementary, Transitional
Methodology
Tier 1 · primary
Courts. Gazettes. National archives.
Tier 2 · corroborating
OCCRP. HRW. BudgIT. TheCable.
Redline
Wikipedia is never a source.