What engine was used during the race driven by Jan Lammers using a chassis of d3 d4, making a tyre of g and rounds of 4-6?
CREATE TABLE "drivers_and_constructors" (
  "constructor" text,
  "chassis" text,
  "engine" text,
  "tyres" text,
  "driver" text,
  "rounds" text
);
SELECT "engine" FROM "drivers_and_constructors" WHERE "tyres"='g' AND "chassis"='d3 d4' AND "driver"='jan lammers' AND "rounds"='4-6';