What type of surface did the tournament canada f9, markham have?
CREATE TABLE "singles_19_13_titles_6_runners_up" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent" text,
  "score" text
);
SELECT "surface" FROM "singles_19_13_titles_6_runners_up" WHERE "tournament"='canada f9, markham';