University of Milan-Bicocca, A. M. 5-6-2002 On the Busta 23 X 11, Geometry, Octahedron, Ema, Meter, Freistempel, Affranc. - Other
Università Milano-Bicocca, A. M. 5-6-2002 Su Busta 23 X 11, Geometria, Ottaedro, Ema, Meter, Freistempel, Affranc. Mecc. - Altri