The Outsiders has genre Young-adult fictionYoung-adult fiction has examples: Wicked LovelyWicked Lovely has genre Young-adult fiction. Young-adult fiction has examples: This Lullaby
[Human]: I love the book The Outsiders. Can you recommend any similar book? [Assistant]: Yes, it is a series and the next series is That was Then, This is Now. They are young-adult fiction. Do you like young adult fiction? [Human]: Yes, I like it since I read Wicked Lovel, I really enjoyed that book. 
If you like that then you'll enjoy The Lullaby