@techreport {TR-1985-012,
   type = {Technical Report},
   author = {Lajos Ronyai },
   title = {Zero Divisors and Invariant Subspaces},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = TR-1985-012,
   year = 1985,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/TR-1985-012.pdf}},
}