Ponzada, A.C.
Bolet¡n Medusa ; no. 2 - Cleveland-US : Medusa Portal Cement Company, 1935. - páginas 5-9 - Irregular - Vol.5, no. 2(Abr/Jun 1935) - Bolet¡n Medusa ; no. 2 . - Medusa Portal Cement Company. .
Bolet¡n Medusa ; no. 2 - Cleveland-US : Medusa Portal Cement Company, 1935. - páginas 5-9 - Irregular - Vol.5, no. 2(Abr/Jun 1935) - Bolet¡n Medusa ; no. 2 . - Medusa Portal Cement Company. .