Books
Herrmann, F. (2018). Patents on the Soles of Your Shoes, (Volume I, 2013). Amazon: CreateSpace.
ISBN-13: 978-1542406741.
Available at Amazon.con
Herrmann, F. (2020). Patents on the Soles of Your Shoes, (Volume II, 2014). Amazon: KDP.
ISBN-13: 978-1542406550.
Available at Amazon.con
Herrmann, F. (2022). Patents on the Soles of Your Shoes, (Volume III, 2015). Amazon: KDP.
ISBN-13:978-1542406352.
Available at Amazon.con