What are the budget type codes for those?
SELECT T2.Budget_Type_Code FROM Documents_with_expenses AS T1 JOIN Ref_Budget_Codes AS T2 ON T1.Budget_Type_code   =   T2.Budget_Type_code WHERE T2.budget_type_Description   =   "Organisation"
budget type codes refer to Budget_Type_Code; Documents_with_expenses and Ref_Budget_Codes are tables; JOIN is used to combine rows from two or more tables based on a related column between them; the related column is Budget_Type_code; budget_type_Description = 'Organisation' specifies a condition for filtering records.