Using simplifying assumptions that are related to the time reversal symmetry, a 1-dimensional family of 8-stage pseudo-symplectic Runge-Kutta methods of order (4, 8) is derived. An example of 7-stage method of order (4, 9) is given.

翻译：利用与时间反演对称性相关的简化假设，推导出含单参数的一族(4,8)阶八级伪辛Runge-Kutta方法。文中还给出一个(4,9)阶七级方法的算例。