CREATE TABLE table_204_843 (id DECIMAL, "volume" DECIMAL, "year" TEXT, "names" TEXT, "articles" DECIMAL, "pages" DECIMAL, "images" DECIMAL, "maps" DECIMAL, "number of copies" DECIMAL)

which volume had the least number of images ?
SELECT "volume" FROM table_204_843 ORDER BY "images" LIMIT 1
SELECT "volume" FROM "table_204_843" ORDER BY "images" NULLS FIRST LIMIT 1