Hulman Panjaitan, Erni Murniarti, Dewa Ayu Widyan, L.Elly AM Pandiangan, and Poltak Siringoringo, “LEGAL CERTAINTY TOWARD ADVOCATE PROFESSIONAL SPECIAL EDUCATION IN INDONESIA”, J Arch.Egyptol, vol. 17, no. 4, pp. 1638-1651, Dec. 2020.