The book has no illustrations or index. It may have numerous typos or missing text. However, purchasers can download a free scanned copy of the original rare book from the publisher's website (GeneralBooksClub.com). You can also preview excerpts of the book there. Purchasers are also entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Original Publisher: Washington, Scientific and Technical Information Office, National Aeronautics and Space Administration; [for sale by the Supt. of Docs., U. S. Govt. Print. Off.]; Publication date: 1973; Subjects: Gamma ray astronomy; Astrophysics; X-ray astronomy; Gamma ray spectrometry; Nature / Star Observation; Science / Astronomy; Science / Astrophysics