In English:

Peggy Pace

Lifespan Integration: Connecting Ego States  through Time (2015 rev.)

Catherine Thorpe

The Healing Timeline: God's Shalom for the Past, Present and Future (2009)

The Success and Strategies of Lifespan Integration (2012)

In French:

Peggy Pace

Pratiquer l'ICV : L'Intégration du Cycle de la Vie (2014)

Catherine Thorpe

Les stratégies thérapeutiques de l'ICV (2016)

Joanna Smith

Psychothérapie de la dissociation et du trauma (2016)

(With various articles about Lifespan Integration, including the chapter "La dissociation de l’enfant en ICV" by Anandi Janner Steffan)

Applications Clinique de l’ICV (2017) 

(Two chapters - "Setting et modèles théoriques de l’ICV" - by Anandi Janner Steffan)

https://www.lifespanintegration.ch

https://lifespanintegration.com/

http://www.aficv.com/

https://lifespanintegration.com/uk/

http://www.ibp-institut.ch/ausbildung/kurse-und-seminare/lifespan-integration/