Lions's computer science courses (6.602B and 6.657G, mentioned in the introduction of the book) at the University of New South Wales. UNSW had actually obtained UNIX source code in 1975, in response to a 1974 query to Dennis Ritchie at Bell. Bell Labs was a subsidiary of AT&T, under restrictions owing to its monopolistic nature as a national telecommunications infrastructure provider, and not permitted to conduct business in any other field, and so was not at liberty to profit from sale of software, however UNIX was being provided under license by another AT&T subsidiary, Western Electric at least by 1977. The UNIX User's group, USENIX's newsletter, UNIX News, of March 1977, announced the availability of the book to UNIX licensees. Note that the newsletter's own strongly worded circulation restriction notice, could only ever have applied within the framework of existing licenses to the licensees with agreements held with the mentioned organisations, not to non-licensees, as a matter of civil contract—the newsletter displays no evidence of governmental authority of the type which might allow general suppression of circulation, such as national security Top Secret classification.) Difficulty in keeping pace with the book's popularity, meant that by 1978 it was available only from AT&T Bell Labs. For many years, the Lions book was the only UNIX kernel documentation available outside Bell Labs. Although the license of 6th Edition allowed classroom use of the source code, the license of 7th Edition specifically excluded such use, so subsequent to this, the book, based on the more liberally licensed version, spread widely through copy machine reproductions, made arguably under various excuses, including (but not limited to!) generous educational licensing terms afforded the publishing institution by the source code owner, as well as various copyright exemptions protecting discussion of mathematical work, though in the shadow of increasing political pressure to erode such rights, as technological means to ‘self-copy’ -- and even self-publish—works became cheaper, more efficient, and more prolific. UNIX itself, was one of these, having been a successful innovation financed at Bell in order to facilitate publishing of technical manuals in-house. When AT&T announced UNIX Version 7 at USENIX in June 1979, the academic/research license no longer automatically permitted classroom use. However, thousands of computer science students around the world spread photocopies. As they were not being taught it in class, they would sometimes meet after hours to discuss the book. Many pioneers of UNIX