Boletín de la Sociedad Matemática Mexicana (2)

W. S. Massey and F. P. Peterson
On the dual Stiefel-Whitney classes of a manifold
pages 1-13

Daniel M. Kan
On torsionfree, torsion and primary spectra
pages 14-19

Wu-Chung Hsiang
On Wu's formula of Steenrod squares on Stiefel-Whitney classes
pages 20-25

Julio Rafael Bastida
Grupos y homomorfismos asociados con un semigrupo
pages 26-45

Carlos Imaz and Zdeněk Vorel
Cierto tipo de estabilidad
pages 46-52

José Adem and Samuel Gitler
Secondary characteristic classes and the immersion problem
pages 53-78

C. Imaz and Z. Vorel
On domains of controllability of proper and normal systems
pages 79-88