What are the notes regarding the scout x-4 vehicle which ceased operation in June 1971?
CREATE TABLE "program_details" (
  "name" text,
  "launched" text,
  "vehicle" text,
  "ceased_operation" text,
  "notes" text
);
SELECT "notes" FROM "program_details" WHERE "vehicle"='scout x-4' AND "ceased_operation"='june 1971';