Joel Newman's casebook has helped law students learn about income taxation since 1998. For the sixth edition, he is joined by long-time adopter Dorothy Brown. The casebook introduces students to many of the materials used by working tax lawyers, including cases, rulings, committee reports, and a Congressional colloquy. New materials include Revenue Ruling 2013-17 on same sex marriage, plus new cases on causation, dependents, deductions for the expenses of medical marijuana dispensaries, and some fun new problems.