Published in Jornal de sciencias mathematicas, physicas e naturaes, in 1873, in volume 4, pages 201-207

Published in Jornal de Sciências, Mathemáticas, Physicas e Naturaes. Lisbõa, in 1873, in volume 4, pages 209-227

Published in Jornal de Sciencias Mathematicas, Physicas e Naturaes, Lisboa, in 1873, in volume 4, pages 228-232

Published in Jor. Sci. math. phys. nat. Lisboa, in 1873, in volume 4, pages 247-253