Vatiwutipong, P.
Phewchean, N. https://orcid.org/0000-0002-3796-3527
Funding for this research was provided by:
Centre of Excellence in Mathematics (1)
Article History
Received: 11 February 2019
Accepted: 24 June 2019
First Online: 8 July 2019
Competing interests
: The authors declare that they have no competing interests.
: Both authors have seen and approved the submission of this manuscript.