Suksamran, Jeerawan
Lenbury, Yongwimon https://orcid.org/0000-0002-8270-1980
Funding for this research was provided by:
Centre of Excellence in Mathematics, Thailand
Article History
Received: 29 January 2019
Accepted: 14 May 2019
First Online: 27 May 2019
Competing interests
: The authors declare that they have no competing interests.