CREATE TABLE table_18090 ("#" FLOAT, "Title" TEXT, "Director" TEXT, "Writer ( s ) " TEXT, "Originalairdate" TEXT, "Repeatairdate ( s ) " TEXT, "Prod.Code" TEXT)

who is the writer of the episode with prod.code 30-17
SELECT "Writer(s)" FROM table_18090 WHERE "Prod.Code" = '30-17'
SELECT "Writer(s)" FROM "table_18090" WHERE "Prod.Code" = '30-17'