By using only the citation, state which court issued each of the following decisions. If you cannot determine which court by looking at the citation only, say so.
a. Douglas, Christopher, T. C. Memo 1994-519
b. Takaba, Brian G., 119 T. C. 285
c. Botts, Roy R., T. C. Summary Opinion 2001-182
d. American Airlines, Inc., 40 Fed. Cl. 712