CREATE TABLE table_51265 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Original air date" TEXT, "Production code" TEXT)

What is the production code of the episode before season 8, with a series number less than 31, and aired on September 21, 1995?
SELECT "Production code" FROM table_51265 WHERE "Season #" < '8' AND "Series #" < '31' AND "Original air date" = 'september 21, 1995'
SELECT "Production code" FROM "table_51265" WHERE "Original air date" = 'september 21, 1995' AND "Season #" < '8' AND "Series #" < '31'