Our book "The Sound - of the Unheard Sense of Life" was published in October 2010 by Koesel Verlag (Munich) | the 12th edition appeared in December 2017 | 352 pages. The book was sold more than 100.000 times (German). The English edition will appear in 2019 by Eerdmans Publishing.

Our second book "Herztöne" was published in 2016 by adeo-Verlag (Asslar). The third edition appeared in 2017.