LO$\mathrm{.}2,4$ Using the legend provided, classify each of the following tax sources:

Legend

P $=$ Primary tax source

S $=$ Secondary tax source

B $=$ Both

N $=$ Neither

a$)$ Sixteenth Amendment to the U$.$S$.$ Constitution. P

b$)$ Tax treaty between the United States and India. S

c$)$ Revenue Procedure. S

d$)$ An IRS publication. S

e$)$ U$.$S$.$ District Court decision. P

f$)$ Yale Law Journal article. N

g$)$ Temporary Regulations $($issued $2019).$ B

h$)$ U$.$S$.$ Tax Court Memorandum decision. P

i$)$ Small Cases Division of the U$.$S$.$ Tax Court decision. P

j$)$ House Ways and Means Committee report. S

k$)$ Notice. S