Kernrechtsfrage
Whether the appellant’s university years from 1951 to 1959 must be counted as AVS contribution years.
Extrahierter Entscheid
The study years could not be added because strict proof of payment of student contributions was not established.
Extrahierte Begründung
The account record contained no entries, and the available university and residence documents did not prove payment of AVS student contributions with the strict certainty required by Art. 141 para. 3 RAVS.