(2014) Book: "Nightmares!". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 0385744250
(2018) Book: "OtherEarth". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 1101939362
(2016) Book: "Nightmares! The Lost Lullaby". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 0385744293
(2017) Book: "Otherworld". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 110193932X
(2016) Book: "Nightmares! The Sleepwalker Tonic". Co-authored with Kirsten Miller. New York: Yearling Press. ISBN-10: 0385744285
(2017) Book: "Everything You Need to Know About Nightmares! and How to Defeat Them: The Nightmares! Handbook". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 0385744315
(2019) Book: "OtherLife". Co-authored with Kirsten Miller. New York: Delacorte Press. ISBN-10: 11019394000