Markham, C. R. (1876). The threshold of the unknown region. Fourth edition with supplementary chapters (4a. ed.). Sampson Low, Marston, Searle & Rivington.
Chicago-Zitierstil (17. Ausg.)Markham, Clements Robert. The Threshold of the Unknown Region. Fourth Edition with Supplementary Chapters. 4a. ed. Londres: Sampson Low, Marston, Searle & Rivington, 1876.
MLA-Zitierstil (9. Ausg.)Markham, Clements Robert. The Threshold of the Unknown Region. Fourth Edition with Supplementary Chapters. 4a. ed. Sampson Low, Marston, Searle & Rivington, 1876.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.