APA (7th ed.) Citation

J. W. Opie & Adam Matthew Digital (Firm). (2018). Nigeria: Niger: Original papers, missionaries: J. W. Opie. Adam Matthew Digital.

Chicago Style (17th ed.) Citation

J. W. Opie and Adam Matthew Digital (Firm). Nigeria: Niger: Original Papers, Missionaries: J. W. Opie. Marlborough, Wiltshire: Adam Matthew Digital, 2018.

MLA (9th ed.) Citation

J. W. Opie and Adam Matthew Digital (Firm). Nigeria: Niger: Original Papers, Missionaries: J. W. Opie. Adam Matthew Digital, 2018.