Using the legend provided, classify each of the following tax sources.
P = Primary tax source
S = Secondary tax source
B = Both
N = Neither
a. Sixteenth Amendment to the U.S. Constitution.
b. Tax treaty between the United States and India.
c. Revenue Procedure.
d. Chief Counsel Advice (issued 2009).
e. U.S. District Court decision.
f. Yale Law Journal article.
g. Temporary Regulations (issued 2013).
h. U.S. Tax Court Memorandum decision.
i. Small Cases Division of the U.S. Tax Court decision.
j. House Ways and Means Committee report.