For engines of Maserati Straight-6 and entrants of H H Gould, what is the latest year?
CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);
SELECT MAX("year") FROM "complete_formula_one_world_championship_" WHERE "engine"='maserati straight-6' AND "entrant"='h h gould';