Who was the constructor of the car that Jan Lammers made 7-14 rounds in?
CREATE TABLE "drivers_and_constructors" (
  "constructor" text,
  "chassis" text,
  "engine" text,
  "tyres" text,
  "driver" text,
  "rounds" text
);
SELECT "constructor" FROM "drivers_and_constructors" WHERE "driver"='jan lammers' AND "rounds"='7-14';