A: No. Sugiyono's work is primarily in Indonesian (Bahasa Indonesia). If your thesis requires English sources, you should cite international authors (Creswell, Kothari) alongside Sugiyono.
However, there is a significant ethical and legal grey area regarding copyright (Hak Cipta). Sugiyono’s books are published by , a reputable publisher. Distributing pirated PDFs violates Indonesian copyright law (Undang-Undang No. 28 Tahun 2014 tentang Hak Cipta). Pdf Buku Metode Penelitian Sugiyono