@incollection {MR2371881,
    AUTHOR = {Kawski, Matthias and Taylor, Thomas J.},
     TITLE = {Canonical operators on graphs},
 BOOKTITLE = {Modeling, estimation and control},
    SERIES = {Lecture Notes in Control and Inform. Sci.},
    VOLUME = {364},
     PAGES = {221--237},
 PUBLISHER = {Springer},
   ADDRESS = {Berlin},
      YEAR = {2007},
   MRCLASS = {93C10 (05C10 05C20 57M15 93B05)},
  MRNUMBER = {MR2371881 (2008k:93087)},
MRREVIEWER = {Gh. Piti{\c{s}}},
}