Sir Norman Lockyer (1899). Nature. Macmillan Journals Limited. p. 496. https://books.google.com/books?id=2vIyAQAAMAAJ&pg=PA496. "The keynote of his views is expressed in the title of a photograph of the Kilik Pass, which is described as one of the few passes by which India might be invaded. We presume that the Mintaka is another. But ... with which even a small undisciplined force can stop a whole army, when acting in difficult ground and on the defensive."