The average of nonzero solutions of second-order ordinary differential system x′ = -[y]2q-2y, y′ = f(x), x(t1) = x(t2) = 0 are obtained if 2q > 1, f(x) ∈ C1(R, R), and uf(u) > 0 for u > 0 is obtained. © 2003 Elsevier Science Ltd. All rights reserved.
Yang, X. (2003). Generalized averages for solutions of nonlinear systems. Mathematical and Computer Modelling, 37(1–2), 51–55. https://doi.org/10.1016/S0895-7177(03)80005-5