APA (7th ed.) Citation

Markham, C. R. (1876). The threshold of the unknown region. Fourth edition with supplementary chapters (4a. ed.). Sampson Low, Marston, Searle & Rivington.

Chicago Style (17th ed.) Citation

Markham, Clements Robert. The Threshold of the Unknown Region. Fourth Edition with Supplementary Chapters. 4a. ed. Londres: Sampson Low, Marston, Searle & Rivington, 1876.

MLA (9th ed.) Citation

Markham, Clements Robert. The Threshold of the Unknown Region. Fourth Edition with Supplementary Chapters. 4a. ed. Sampson Low, Marston, Searle & Rivington, 1876.