1. J. W. Tukey, Conf. Rec. EASCON’74, (1974) p. 673
2. J.W. Tukey, Exploratory Data Analysis (Addison-Wesley, Mento Park, 1977)
3. W. K. Pratt, Digital Image Processing (Wiley, New York, 1978)
4. A.C. Bovik, T. Huang, D. Munson, IEEE Trans. Acoust. Speech Signal Process. 31, 1342 (1983)
5. D.R.K. Brownrigg, Commun. ACM 27, 807 (1984)