Dr. Sue Johnson, the originator of Emotionally Focused Couple Therapy has written a great book, which has proven to be an invaluable tool for enhancing and speeding up the therapy process. The book is called "Hold me tight" and is available via amazon.de.

"Hold me tight" Hardcover

"Hold me tight" Paperback

Another excellent read on the theory and science of love is a book titled "A General Theory of Love" written by Thomas Lewis, Fari Armini and Richard Lannon. This is also available via amazon.de

"A General Theory of Love"