Multiple independent sources — including National Geographic Indonesia, an academic library, and a museum registry — consistently confirm Martha Christina Tiahahu was designated a National Hero of Indonesia on May 20, 1969, via Presidential Decree No. 012/TK/Tahun 1969. No source in the evidence pool contradicts this date or designation. The only limitation is that the primary decree text itself is not reproduced, but the convergence of specific details across diverse secondary sources meets the standard threshold for historical verification.