@techreport {TR-1990-013,
   type = {Technical Report},
   author = {Keith Linn Downing },
   title = {The Use of Teleology in the Qualitative Evaluation and Explanation of Circulatory Systems},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = TR-1990-013,
   month = 11,
   year = 1990,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/TR-1990-013.pdf}},
}