What's the total points that Scuderia Ferrari with a Ferrari V12 engine have before 1971?
CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);
SELECT SUM("points") FROM "complete_formula_one_world_championship_" WHERE "year"<1971 AND "entrant"='scuderia ferrari' AND "engine"='ferrari v12';