APA-viite (7. p.)

Nigeria. Federal Inland Revenue Service, ebrary, Inc, & Okauru, I. O. (2012). FIRS handbook on reforms in the tax system (2004-2011). Safari Books.

Chicago-viite (17. p.)

Nigeria. Federal Inland Revenue Service, Inc ebrary, ja Ifueko Omoigui Okauru. FIRS Handbook on Reforms in the Tax System (2004-2011). Ibadan, Nigeria: Safari Books, 2012.

MLA-viite (9. p.)

Nigeria. Federal Inland Revenue Service, et al. FIRS Handbook on Reforms in the Tax System (2004-2011). Safari Books, 2012.