What is the oldest written source in this country that mentions this right?
São Tomé and Príncipe
Article 30 of Sao Tome and Principe’s 1975 Constitution protects press freedom: “Freedom of the press is guaranteed in the Democratic Republic of São Tomé and Príncipe, within the terms of the law. The State guarantees a public service press independent of the interests of economic and political groups" (Constitute Project, “São Tomé and Príncipes’s Constitution of 1975 with Amendments through 2003”).