Table schema:
CREATE TABLE CMI_Cross_References (master_customer_id VARCHAR, source_system_code VARCHAR); CREATE TABLE Customer_Master_Index (cmi_details VARCHAR, master_customer_id VARCHAR)

Question: what are the details of the cmi masters that have the cross reference code 'Tax'?
SQL: SELECT T1.cmi_details FROM Customer_Master_Index AS T1 JOIN CMI_Cross_References AS T2 ON T1.master_customer_id = T2.master_customer_id WHERE T2.source_system_code = 'Tax'