CREATE TABLE Benefits_Overpayments (council_tax_id VARCHAR, cmi_cross_ref_id VARCHAR)
CREATE TABLE CMI_Cross_References (source_system_code VARCHAR, cmi_cross_ref_id VARCHAR)

What is the tax source system code related to the benefits and overpayments? List the code and the benifit id, order by benifit id.
SELECT T1.source_system_code, T2.council_tax_id FROM CMI_Cross_References AS T1 JOIN Benefits_Overpayments AS T2 ON T1.cmi_cross_ref_id = T2.cmi_cross_ref_id ORDER BY T2.council_tax_id
SELECT "T1"."source_system_code", "T2"."council_tax_id" FROM "CMI_Cross_References" AS "T1" JOIN "Benefits_Overpayments" AS "T2" ON "T1"."cmi_cross_ref_id" = "T2"."cmi_cross_ref_id" ORDER BY "T2"."council_tax_id" NULLS FIRST