Which nation is where rider phillip dutton from?
CREATE TABLE "table1_18666752_3" (
  "nation" text,
  "rider" text,
  "horse" text,
  "cross_country_penalties" text,
  "total_penalties" text,
  "total_team_penalties" text,
  "team_rank" real
);
SELECT "nation" FROM "table1_18666752_3" WHERE "rider"='Phillip Dutton';