Why is the Dynamic learning Series not avalable in Safari?

Why are the books from the Dynamic Learning Series not avalable in Safari? I subscribed to Safari and I really like it, but then I noticed that there are many O'Reilly books missing in the Safari Catalogue. Can you tell me why? What are the criterias that apply to the decision if a published O'Reilly book shows up in Safari or not?
Inappropriate?
1 person has this question
User_default_medium