What is the score of the match on 3 March 1988 at the estadio nacional?
CREATE TABLE "international" (
  "season" real,
  "date" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "venue" text,
  "competition_round" text
);
SELECT "score" FROM "international" WHERE "venue"='estadio nacional' AND "date"='3 march 1988';