确定有限级数解的阶数上界的一种 n阶展开方法
宋宸苇, 柳银萍
An n-order expansion method for determining the upper bound of the order of finite series solutions
Chenwei SONG, Yinping LIU
华东师范大学学报(自然科学版) . 2021, (3): 56 -64 .  DOI: 10.3969/j.issn.1000-5641.2021.03.007