An Introduction to Kolmogorov Complexity and Its Applications, Springer, 2019, Fourth Edition Google's search for meaning at Newscientist.com. J. Poland and Th. Zeugmann (2006), Clustering the Google Distance with Eigenvectors and Semidefinite Programming A. Gupta and T. Oates (2007), Using Ontologies and the Web to Learn Lexical Semantics (Includes comparison of NGD to other algorithms.) Wong, W., Liu, W. & Bennamoun, M. (2007) Tree-Traversing Ant Algorithm for Term Clustering based on Featureless Similarities. In: Data Mining and Knowledge Discovery, Volume 15, Issue 3, Pages 349–381. (the use of NGD for term clustering) Computational linguistics Statistical distance