I don't know any Spanish, but, thanks to the Babelfish translator, I now know that the organisation going by the rather wonderful name of the Sindicato de Trabajadores de la Escuela Normal Superior translates (approximately) into English as The Union of Workers of the Superior Normal School. Which is kind of interesting.
Why the sudden interest in a Mexican trade union? Well, their web address happens to be stense.com
Postscript: Some years later, I am happy to report, the union relinquished its web domain, so I snapped it up at a bargain price.