Presiding at sitting of the National Assembly and at joint sittings
Section 53(1)(a) · 1999 Constitution (2004 edition)
What Constitution says
(a) in the case of the Senate, the President of the Senate shall preside, and in his absence the Deputy President shall preside; and
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 44. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections