@techreport {DRP-201903-Johnson,
   type = {Directed Research Project},
   author = {Alister Johnson},
   title = {Scaling Collaborative Filtering with PETSc},
   institution = {University of Oregon, Computer and Information Sciences Department},
   number = DRP-201903-Johnson,
   month = 3,
   year = 2019,
   note = {Available at \url{https://www.cs.uoregon.edu/Reports/DRP-201903-Johnson.pdf}},
}