Hold Me Tight: Seven Conversations for a Lifetime of Love
By Sue Johnson

The Attachment Theory Workbook: Powerful Tools to Promote Understanding, Increase Stability, and Build Lasting Relationships
By Annie Chen

Attached: The New Science of Adult Attachment and How It Can Help YouFind - and Keep - Love
Amir Levine and Rachel S.F. Heller

The Power of Attachment: How to Create Deep and Lasting Intimate Relationships
By Diane Poole Heller

Breakups + Discernment (deciding to stay together or not):

Too Good to Leave, Too Bad to Stay: A Step-by-Step Guide to Help You Decide Whether to Stay In or Get Out of Your Relationship
by Mira Kirshenbaum, Adriane McNeely, et al.

An Emotionally Focused Guide to Relationship Loss
By Clare Rosoman