APA
Johnson H. H., . (1892). Opening up of Africa. London: Williams and Norgate.
Chicago
Johnson H H, . 1892. Opening up of Africa. London: Williams and Norgate.
Harvard
Johnson H. H., . (1892). Opening up of Africa. London: Williams and Norgate.
MLA
Johnson H H, . Opening up of Africa. London: Williams and Norgate. 1892.