¿A qué debe su mala fama el martes y trece?

These Spanish resources are based on a short text from Muy interesante explaining the origins of "martes y trece" - see the link below:

There are 9 pdf files in all, all printed using dopdf - http://www.dopdf.com

The pdfs are based on a Mix and Gap file containing the text, which is also included (mtx3). This file provides a wide variety of interactive exercises for use with PCs or with an interactive whiteboard. It requires TaskMagic3. If you haven't got TaskMagic3, you can download a 30-day trial from the TaskMagic website (doesn't require registration or anything - just download and install it).