In the early 2004, the Supreme Court ruled that it is unconstitutional to spend public money on school vouchers used to send students to religious schools

Books and articles written by political scientists and other academics or political practitioners are good examples of ___________ sources.

Fill in the blank(s) with the appropriate word(s).

What type of tax takes a larger percentage of lower income earners' income and a smaller percentage of the income of those who earn more?

A. progressive tax B. direct tax C. indirect tax D. regressive tax E. proportional tax