1. Aracáma-Zorraquén, Ernesto D., In: WIPO. The Role of Patent Information in Research and Development; collection of lectures given at the Moscow Symposium, 1974. Geneva, WIPO. 1975. p. 242.
2. Hill Michael , Patent Documentation. London: Sweet & Maxwell, 1979 . p. 5.
3. Ibid.
4. Ibid.