Li, Ming The period function for quadratic integrable systems with quartic orbits. (Chinese. English summary) Zbl 1212.34121 J. Math. Study 42, No. 3, 329-334 (2009). MSC: 34C25 Periodic solutions to ordinary differential equations 92D25 Population dynamics (general) Keywords:period function; generalized Lotka-Volterra systems; Picard-Fuchs equation; monotonicity PDFBibTeX XMLCite \textit{M. Li}, J. Math. Study 42, No. 3, 329--334 (2009; Zbl 1212.34121)