Which source allows the researcher to locate articles which cite a specific article?

Which of the following is a shared power between states and the federal government?

a. controlling money supply b. raising and maintaining an army c. establishing a post office d. the power to tax

Some Americans favor a tax code that does not favor one kind of economic activity over another. What kind of taxation policy would they support?

a. a regressive tax b. a progressive tax c. tax neutrality d. tax exemption