Size of Senatorial districts and Federal constituencies
Section 72 · 1999 Constitution (2004 edition)
What Constitution says
No Senatorial district or Federal constituency shall fall within more than one State, and the boundaries of each district or constituency shall be as contiguous as possible and be such that the number of inhabitants thereof is as nearly equal to the population quota as is reasonably practicable.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 50. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections