Thor Power Tool Co. v. Commissioner , 99 S. Ct. 773 ( 1979 )
Kornhauser v. United States , 48 S. Ct. 219 ( 1928 )
Cohan v. Commissioner of Internal Revenue , 39 F.2d 540 ( 1930 )
Welch v. Helvering , 54 S. Ct. 8 ( 1933 )
Imperial Type Metal Co. v. Commissioner of Int. Rev. , 106 F.2d 302 ( 1939 )