Author Contribution
Nguyen Vinh Thong and Nguyen Minh Quan conceived of the presented idea.
Nguyen Vinh Thong developed the theory and performed the computations.
Nguyen Xuan Dung verified the analytical methods. Nguyen Minh Quan
encouraged Nguyen Vinh Thong to investigate and supervised the findings
of this work. All authors discussed the results and contributed to the
final manuscript.