The publishing and editorial teams would like to thank the following, for their invaluable service as 2021 reviewers for this journal. We are very grateful for the contributions made. With their help, the journal has been able to publish such high-quality articles:

• Adhinugraha, Kiki Maulana
• Akram, Umair
• Alghamdi, Norah
• Enokido, Tomoya
• Pathak, Bhavik
• Tomy, Sarath
• Wiro Sasmito, Ginanjar
• Woungang, Isaac
• Wu, Pengkun