* Apple Books: Apple Books offers a wide variety of textbooks for iPad, including textbooks from major publishers like McGraw-Hill, Pearson, and Cengage. You can search for textbooks by subject, title, or author, and preview textbooks before you buy them.
* VitalSource: VitalSource is a leading provider of digital textbooks, and offers a variety of textbooks for iPad. You can search for textbooks by subject, title, or author, and VitalSource also offers a variety of features to help you study, such as note-taking, highlighting, and flashcards.
* Amazon Kindle: Amazon Kindle offers a variety of textbooks for iPad, including textbooks from major publishers like McGraw-Hill, Pearson, and Cengage. You can search for textbooks by subject, title, or author, and preview textbooks before you buy them.
* Google Play Books: Google Play Books offers a variety of textbooks for iPad, including textbooks from major publishers like McGraw-Hill, Pearson, and Cengage. You can search for textbooks by subject, title, or author, and preview textbooks before you buy them.
* Barnes & Noble Nook: Barnes & Noble Nook offers a variety of textbooks for iPad, including textbooks from major publishers like McGraw-Hill, Pearson, and Cengage. You can search for textbooks by subject, title, or author, and preview textbooks before you buy them.
In addition to these online retailers, you may also be able to find textbooks for iPad at your local bookstore or library.