Bolted Langevin transducers with leadfree piezoelectric ceramics
C. Scheidemann, P. Bornmann, W. Littmann, T. Hemsel, in: 2025.

Various Aspects of the Placement of a Piezoelectric Material in Composite Actuators, Motors, and Transducers
T. Hemsel, E.G. Lierk, W. Littmann, T. Morita, Journal of Korean Physical Society 57 (2010) 933–937.