Judgment of the Court (Second Chamber) of 18 February 1992 in Case C-5/91 (reference for a preliminary ruling from the Tribunal du Travail, Mons, La Louvière Division (Belgium)): Antonietta Di Prinzio v. Office National des Pensions (Social security for migrant workers — Calculation of benefits — Retirement and survivor's pension — National rules for prevention of overlapping benefits — Interpretation of Article 46 of Regulation (EEC) No 1408/71)