Focus+Context: SpaceTree interactively expand/contract not stretching space [demo: www.cs.umd.edu/hcil/spacetree] [SpaceTree. Catherine Plaisant, Jesse Grosjean and Ben B. Bederson. Proc. InfoVis 2002 ftp://ftp.cs.umd.edu/pub/hcil/Reports-Abstracts-Bibliography/2002-05html/2002-05.pdf] 45