R. Díaz-Hernández, J. García-Barreto, and M. Moreno-Corral, “Digital images of a set of bright shapley ames disk galaxies from San Pedro Mártir glass plates$^{i}$”, Rev. Mex. Fis. E, vol. 55, no. 1 Jan-Jun, pp. 70–84, Jan. 2009.