By services, 22 July, 2022 23 April 1990 Income Tax Severed Letter AC74796 - Scientific Research and Experimental Development - Related Salary Expenditures
By services, 22 July, 2022 30 May 1986 Income Tax Severed Letter 5-1360 - [Tax Treatment of Commodity Futures Income]
By services, 22 July, 2022 13 August 1986 Income Tax Severed Letter 5-1958 - [Interest Components of Damage Awards]