Judgment of the Court (Sixth Chamber) of 21 October 2020.#GR v Stadt Duisburg.#Request for a preliminary ruling from the Verwaltungsgericht Düsseldorf.#Reference for a preliminary ruling – EEC-Turkey Association Agreement – Decision No 1/80 – Article 7, first paragraph – Right of residence of family members of a Turkish worker legally employed in a Member State – Naturalisation of the family member concerned in the host Member State – Maintenance of the right of residence – Acquired rights.#Case C-720/19.