About this article
Published Online: Nov 05, 2020
Page range: 357 - 366
Received: Jul 22, 2020
Accepted: Aug 14, 2020
DOI: https://doi.org/10.2478/amns.2020.2.00042
Keywords
© 2020 Xiuqing Yu et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.
Yu, Xiuqing
School of Mathematics and Big Data, Dezhou UniversityDezhou, P R China
Xu, Fengsheng
School of Mathematics and Big Data, Dezhou UniversityDezhou, P R China