Go to your New Assignment
Scroll all the way down, and click on Add more books +
To add a book, check the box. The book will move to your list.
Additional Tips:
Use the filters to sort through the available books.
While creating a new assignment, you can browse the material in the books you’ve added to your list.
Need to remove a book? Click the subtraction icon (–) to the right of the book's name.
If you remove a book by mistake or notice a book missing from your list, don’t worry! You can always find it in the available books on the left and add it back.