@techreport {TR-1987-011,
   type = {Technical Report},
   author = {Arthur M. Farley },
   title = {Cluster-based Representation of Hydraulic Systems},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = TR-1987-011,
   month = 9,
   year = 1987,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/TR-1987-011.pdf}},
}