Nikki Sixx wrote how many books in the Heroin Diaries series?

Nikki Sixx wrote three books in the Heroin Diaries series:

- The Heroin Diaries: A Year in the Life of a Shattered Rock Star (2007)

- This Is Gonna Hurt: Music, Photography and Life Through the Distorted Lens of Nikki Sixx (2011)

- The First 21: How I Became Nikki Sixx (2013)