What is the StuffitX value that has a Stuffit of unknown, LHA/LZH of yes, and unknown ISO/CD image?
CREATE TABLE "writing" (
  "gzip" text,
  "bzip2" text,
  "lha_lzh" text,
  "stuff_it" text,
  "stuff_it_x" text,
  "iso_cd_image" text
);
SELECT "stuff_it_x" FROM "writing" WHERE "stuff_it"='unknown' AND "lha_lzh"='yes' AND "iso_cd_image"='unknown';