Being a Correlation of the Income Tax Acts of 1926, 1928, 1932, 1934,1936 and 1938, with Amendments, and the Estate Tax Acts of 1916, 1917, 1918, 1921, 1924 and 1926, with Amendments. Also Containing the Gift Tax Acts of 1924 and 1932, with Amendments, the Excess Profits and Capital Stock Taxes Imposed Since 1934, with Amendments, the Provisions of the Act of 1936 with Reference to Unjust Enrichment and Refunds of Processing Taxes, and the Revised Statutes Applicable to Federal Taxation