You must have a 21st century textbook which is an introduction to physics, with calculus, and which includes Modern Physics. If the title of the text does not read "with Modern Physics" or "Extended", then the text is unlikely to cover the required subjects, and you should not purchase it. Farther down on this page, you will find my textbook recommendations. No matter which text you choose, you must have access to Mastering Physics. The easiest way to purchase Mastering Physics is direct online purchase at masteringphysics.com; without etext it is $66 and with etext it is $110. If you are satisfied reading on your computer, then Mastering Physics with etext will satisfy your textbook requirements. (To purchase online, go to the link above, then select "Students", and when asked to indicate your textbook, choose Young and Freedman, 13th edition; you will be given the option of no etext later in the process.) You can also purchase Mastering Physics access from the ASU Bookstore; without etext it is $78 and with etext it is $133. Finally, if you choose to purchase a new hardbound copy of Young and Freedman University Physics with Modern Physics, 13th Edition, you should purchase a copy that includes a Mastering Physics access card; at our bookstore, this should be about $257. ($260 at www.mypearsonstore.com) Textbook Recommendations: Reading assignments, by section number, will be provided for three different textbooks; those are indicated below in order of preference. As indicated in the first paragraph of this page, you may in fact choose any textbook that you wish, but if you choose a text other than one of the three listed below, then you will have to determine the reading assignments for yourself based on our list of lecture topics. The most preferred text is Young and Freedman's University Physics with Modern Physics, 13th Edition. You can also use the older 12th or 11th editions (which should be quite inexpensive if you can find them), but the text that you purchase must include Modern Physics. Also, do not purchase only Volume 1 or Volume 2 or Volume 3, as our subject matter comes from all three volumes. The second most preferred text is Halliday, Resnick, and Walker's Fundamentals of Physics Extended, 9th Edition. You can also use the older 8th or 7th editions, but you must have the Extended text in either case. The posted reading assignments for this text will actually come from the 8th edition. The reading assignments will also be posted for a third text, Serway and Jewett's Physics for Scientists and Engineers with Modern Physics, 8th edition. Some students who have taken PHY121 and 131 here at ASU may already have some version of this textbook (such as the hybrid version, which has all the text, but none of the Serway problems); for those students, this would be the cheapest and most preferred option. You may also use the 7th editon of this text. Thanks. GBA