Sadyrbaev, F., and A. Gritsans. “Nonlinear Spectra for Parameter Dependent Ordinary Differential Equations”. Nonlinear Analysis: Modelling and Control 12, no. 2 (April 25, 2007): 253–267. Accessed April 11, 2025. https://www.journals.vu.lt/nonlinear-analysis/article/view/14715.