1. Qin Yuan-xun, Lecture on General Problems of Motion Stability, (in Chinese), Science Publishing House, Beijing, (1958).
2. Qin Yuan-xun, On periodic solutions of Riccati's Equation with periodic coefficients, (in Chinese), Kexue Tongbao, 24, 23 (1979), 1062–1066.
3. Zahal-Itkin, M. H., Riccati matrix differential equation and semi-group of fractional linear transformations (in Chinese), YMH, 28. 3(171) (1973), 83–120.
4. Li Hong-xiang, Some new integrable types of ordinary differential equations, (in Chinese), Practice and Knowledge of Mathematics, 1 (1980), 46–51.
5. Demidovich, B. P., Collection of Problems and Exercises on Mathematical Analysis, National Publishing House of Phys. and Math. Literature, Moscow, (1958), p. 2267.