Silitonga, Arridina Susan https://orcid.org/0000-0002-0065-8203
Hassan, Masjuki Haji
Ong, Hwai Chyuan
Kusumo, Fitranto
Funding for this research was provided by:
Ministry of Education of Malaysia and The University of Malaya, Kuala Lumpur, Malaysia (BKS054-2017)
Politeknik Negeri Medan (UPPM-2017)