Sextro, Walter, Karl Popp, and I Wolter. “Vibrational Behaviour of Tuned and Detuned Bladed Disks with Friction Dampers.” In International Congress on Combustion Engines, Proceedings of the 22nd CIMAC, 1:257–70. Kopenhagen, D\'22anemark, 1998.

Sextro, Walter, Karl Popp, and I Wolter. “Three-Dimensional Vibration of Bladed Disk Assemblies with Friction Dampers.” In The 7th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Proceedings of ISROMAC-7, B:621–30. Honolulu, Hawaii, USA, 1998.

Goldschmidt, Stefan, Tobias Hemsel, Jürgen Krome, Heiner Storck, and Jörg Wallaschek. “Schwingungsprüfstand Zur Vollautomatischen Messung von Ultraschallschwingungen in Piezoelektrischen Antrieben.” In Tagungsband Zum 4. Laser Vibrometer Seminar Der Polytec GmbH. Waldbronn, Deutschland, 1997.

Hemsel, Tobias, and Jörg Wallaschek. “Ultrasonic Motors for Linear Positioning Tasks in Automobiles.” In Proceedings of the 30th International Symposium on Automotive Technology \'26; Automation (ISATA), 631–37. Florenz, Italien, 1997.

Hemsel, Tobias, and Jörg Wallaschek. “Piezoelectric Ultrasonic Linear Motors.” In EUROMECH, European Mechanics Colloquium “Synthesis of Mechatronic Sytems.” Duisburg, 1997.

Popp, Karl, and Walter Sextro. “Schwingungsverhalten von Verstimmten Beschaufelungen Mit Reibelementen.” In Forschungsvereinigung Verbrennungskraftmaschinen (FW) -Lnformationstagung Turbinen, 131–42. Frankfurt am Main, Germany, 1997.

Sextro, Walter. “Schwingungsverhalten von Schaufelkränzen Mit Reibelementen Bei Frequenzverstimmung.” In VDI-Reihe, Vol. 11. VDI-Verlag, Düsseldorf, 1997.

Sextro, Walter, Karl Popp, and Ivo Wolter. “Improved Reliability of Bladed Disks Due to Friction Dampers.” In The 1997 International Gas Turbine \'26; Aeroengine Congress \'26; Exposition, 1997.

Popp, Karl, and Walter Sextro. “Schwingungsverhalten Eines Schaufelkranzes Mit Reibelementen Bei Frequenzverstimmung.” In Forschungsvereinigung Verbrennungskraftmaschinen (FW) - Lnformationstagung Turbinen, 53–76. Frankfurt am Main, Germany, 1996.

Popp, Karl, and Walter Sextro. “Dynamical Behaviour of a Bladed Disk with Friction Dampers.” In The 2nd European Nonlinear Oscillation Conference - Proceedings of EUROMECH, 1:157–83. Prag, 1996.

Sextro, Walter, and B Schmalhorst. “Static Behaviour of Drill Strings in Curved Boreholes.” Zeitschrift Für Angewandte Mathematik Und Mechanik (ZAMM) 73 (1993): 255–57.

Stelter, Peter, and Walter Sextro. “Bifurcations in Dynamic Systems with Dry Friction.”https://doi.org/10.1007/978-3-0348-7004-7_44__In Bifurcation and Chaos: Analysis, Algorithms, Applications, edited by R. Seydel, F.W. Schneider, T. Küpper, and H. Troger, 97:343–47. International Series of Numerical Mathematics / Internationale Schriftenreihe Zur Numerischen Mathematik / S\rquote erie Internationale d’Analyse Num\rquote erique. Birkhäuser Basel, 1991.https://doi.org/10.1007/978-3-0348-7004-7_44 .