von Osmanski, Sebastian, et al. “On the Incorporation of Friction Into a Simultaneously Coupled Time Domain Model of a Rigid Rotor Supported by Air Foil Bearings”. Technische Mechanik - European Journal of Engineering Mechanics, vol. 37, no. 2-5, June 2019, pp. 291-02, doi:10.24352/UB.OVGU-2017-105.