Unregistered Marriage and the Legal Impact, A Book Review â€œKepastian Hukum Perkawinan Siri dan Permasalahannyaâ€ Zainuddin SH MH & Afwan Zanuddin SH MH, Deepublish Yogyajarta, 95 Pages, ISBN: 978-602-435-120-1 - Gufron, Dede Muhamad (Indonesian Journal of Advocacy and Legal Services, 2021)