This issue consists of 5 articles from 20 authors affiliated with 5 institutions from 2 countries including:

• Japan (Mie University)
• Indonesia (Universitas Jenderal Achmad Yani, Universitas Pendidikan Indonesia, Sultan Ageng Tirtayasa University, Nusa Putra University, Sukabumi Polytechnic)

This issue consists of 6 articles from 16 authors affiliated with 4 institutions from 2 countries including:

• Indonesia (Universitas Pendidikan Indonesia, Siliwangi University, Nusa Mandiri University, Nusa Putra University and Sukabumi Polytechnic)
• Nigeria (Ahmadu Bello University)

This issue consists of 5 articles from 14 authors affiliated with 4 institutions from Indonesia including Universitas Pendidikan Indonesia, Siliwangi University, Sultan Ageng Tirtayasa University and Nusaputra University.

This issue consists of 5 articles from 19 authors affiliated with 7 institutions from 3 countries including:

• Indonesia (Universitas Pendidikan Indonesia, Institut Teknologi Telkom Purwokerto, Sultan Ageng Tirtayasa University, Universitas Langlangbuana, Universitas Jenderal Achmad Yani)
• Japan  (Shibaura Institute of Technology)
• Vietnam (Hanoi University of Science and Technology)