@techreport {TR-1999-002,
   type = {Technical Report},
   author = {Arthur Farley, Paraskevi Fragopoulou, David Krumme, Andrzej Proskurowski, Dana Richards},
   title = {Multi-Source Spanning Tree Problems},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = TR-1999-002,
   month = 2,
   year = 1999,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/TR-1999-002.pdf}},
}