https://archive.org/search?query=%22Hak+cipta+bebas+dan+merdeka.%22&sin=TXT
This search on the Internet Archive returns many books which have this copyright statement:
"Hak cipta bebas dan merdeka. Setiap makhluk dianjurkan dan dinasehatkan untuk mengkopi, mencetak, menggandakan, serta menyebar isi serta materi-materi didalamnya."
Is anyone here interested in producing audiobooks from any of them?