SELECT DISTINCT source_system_code FROM cmi_cross_references WHERE source_system_code LIKE '%en%'
Which distinct source system code includes the substring 'en'?
[Schema (values) (types)]: | local_govt_mdm |  Customer_Master_Index : master_customer_id (text) , cmi_details (number) | CMI_Cross_References : cmi_cross_ref_id (text) , master_customer_id (number) , source_system_code (text) | Council_Tax : council_tax_id (text) , cmi_cross_ref_id (number) | Business_Rates : business_rates_id (text) , cmi_cross_ref_id (number) | Benefits_Overpayments : council_tax_id (text) , cmi_cross_ref_id (number) | Parking_Fines : council_tax_id (text) , cmi_cross_ref_id (number) | Rent_Arrears : council_tax_id (text) , cmi_cross_ref_id (number) | Electoral_Register : electoral_register_id (text) , cmi_cross_ref_id (number);