It can be tricky to find the books listed on the Book list page when you look on the schedules. Occasionally something has been dropped or moved from the List or the Schedule and they no longer match, but more often the book is only used part of the year and thus might be harder to find when glancing over the schedule. We live overseas so I have to purchase books WAY FAR in advance of the term, and I have overlooked books of-so-many-times on my initial read-through. It is good to ask here, as you did, to sort it out.
"How easy it is to fly on paper wings!" (Helen Keller)