Welcome to the official webpage of Dr. Roto. Students may contact me via email roto05@ugm.ac.id.  Colleagues and students can also reach me at my office, Graduate School Building (Gedung S2/S3) 1F, by appointment. For urgent issues, voice and texting are welcome. Have a great learning experience at UGM. For guests, have a great association with UGM. https://scholar.google.co.id/citations?user=ugRr8oAAAAAJ&hl=en