Aethant ati eisoes i gwblhau cytundeb cydweithredu (a ddaw i rym ym 1999) ä'r Aelod Wladwriaethau a arwyddodd Gytundeb Schengen.
They have accordingly concluded a cooperation agreement — due to enter Into force in 1999 — with the Member States that have signed the Schengen Agreement.