Published in Jornal de Sciências, Mathemáticas, Physicas e Naturaes. Lisbõa, in 1870, in volume 3, pages 57-65

Created: 2012-02-19, modified: 2012-03-23

Published in J. Sci. math. phys. nat., in 1870, in volume 3, pages 123-127

Created: 2013-08-13, modified: 2013-08-13