@techreport {TR-1990-004,
   type = {Technical Report},
   author = {William Robinson, Stephen Fickas},
   title = {Negotiation Freedoms for Requirements Engineering},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = TR-1990-004,
   month = 4,
   year = 1990,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/TR-1990-004.pdf}},
}