Published in Atti Della Societa Italiana Milano, in 1932, in volume 71, pages 138-144

Published in Atti Della Societa Italiana Milano, in 1932, in volume 71, issue 1, pages 39-49

Published in Atti della Societa Italiana Milano, in 1932, in volume 71, issue 1, pages 58-60

Published in Atti della Societa Italiana Milano, in 1932, in volume 71, issue fasc. 2, pages 119-125