Commissioner v. Groetzinger ( 1987 )
Cohan v. Commissioner of Internal Revenue ( 1930 )
W. Horace Williams, Sr., and Viola Bloch Williams v. United States ( 1957 )
Welch v. Helvering ( 1933 )
Indopco, Inc. v. Commissioner ( 1992 )
Vanicek v. Commissioner ( 1985 )