O. J. Purata Sifuentes, C. Ángel Arámburo Botello, I. S. Ramírez, J. L. De la O. Martínez, and E. Funes Rodríguez, “Volume measurement of reference weights of pressure balances through optical comparator”, NS, vol. 9, no. 18, pp. 118–132, Mar. 2017.