1. Optische Studien nach der Methode der Schlierenbeobachtung; V. Erscheinungen am elektrischen Funken;Toepler;Pogg. Ann. Phys.,1868
2. A simple schlieren system for visualizing a soundfield of pulsed ultrasound;Kudo,2004
3. “Schlieren visualization of ultrasonic wave fields with high spatial resolution“;Neumann;Ultrasonics,2006
4. Optical measurement and visualization of transient ultrasonic wave fields;Koehler,2003
5. A mode-switchable guided elastic wave transducer;Köhler;J Nondestr Eval,2020