READING ACTS: Christian or Gnostic? – Sibylline Oracle, Book 7. Philip skips from Book 5 to Book 7. He doesn't specify why, but it's probably because Book 6 is just a brief hymn to Christ that doesn't even mention the Sibyl. It's not clear how it ended up the in the collection at all. But perhaps he'll come back to it anyway, since it has some points of interest.
Past posts in the series on the Sibylline literature are noted here and links. I have some comments on Sibylline Oracles Book 5 in that post. Cross-file under Old Testament Pseudepigrapha Watch.