Popular Electronics, Volume 6, Issue 2–6 (页面存档备份,存于互联网档案馆). Ziff-Davis Publishing Co., Inc. 1974, p. 267. "There are three classifications into which the intelligence community officially divides clandestine broadcast stations. A black operation is one in which there is a major element of deception."
Djang, Chu, From Loss to Renewal: A Tale of Life Experience at Ninety, Authors Choice Press, Lincoln, Nebraska, p. 54. "(A black operation was) an operation in which the sources of propaganda were disguised or misrepresented in one way or another so as not to be attributed to the people who really engineered it."
Popular Electronics, Volume 6, Issue 2–6 (页面存档备份,存于互联网档案馆). Ziff-Davis Publishing Co., Inc. 1974, p. 267. "There are three classifications into which the intelligence community officially divides clandestine broadcast stations. A black operation is one in which there is a major element of deception."