@InProceedings{	  valiente:spire:2001,
  author	= {Gabriel Valiente},
  title		= {An Efficient Bottom-Up Distance between Trees},
  booktitle	= {Proc.\ 8th Int.\ Symposium on String Processing and
		  Information Retrieval},
  year		= {2001},
  publisher	= {IEEE Computer Science Press},
  pages		= {212--219},
  abstract	= {A new bottom-up distance measure for labeled trees, which
		  is based on the largest common forest of the trees and has
		  the threefold advantage of independence of particular edit
		  costs, low complexity, and coverage of ordered and
		  unordered trees, is introduced and related in this paper
		  with other distance measures published in the literature.
		  Algorithms for computing the bottom-up distance in time
		  linear in the number of nodes are given in full detail.}
}