Which rounds did Vic Elford with a Ford cosworth dfv 3.0 v8 engine have?
CREATE TABLE "teams_and_drivers" (
  "constructor" text,
  "chassis" text,
  "engine" text,
  "tyre" text,
  "driver" text,
  "rounds" text
);
SELECT "rounds" FROM "teams_and_drivers" WHERE "driver"='vic elford' AND "engine"='ford cosworth dfv 3.0 v8';