Survey of numerical techniques for grouping.
[This corrects the article on p. 379 in vol. 35.][This corrects the article on p. 381 in vol. 35.][This corrects the article on p. 384 in vol. 35.][This corrects the article on p. 387 in vol. 35.][This corrects the article on p. 388 in vol. 35.][This corrects the article on p. 389 in vol. 35.].