Nice paper by Robert Huber and Jens Klump has appeared in Computers & Geosciences entitled "Charting taxonomic knowledge through ontologies and ranking algorithms" (doi:10.1016/j.cageo.2008.02.016). The paper is not open access, but you can get some background from the post How TaxonRank works. Here's the abstract.

Stumbled across Project Xanadu, Ted Nelson's vision of the way the web should be (e.g., BACK TO THE FUTURE: Hypertext the Way It Used To Be). Nelson coined the term "transclusion", including one document in side another by reference.