Complex sentence: SOE also revived some medieval devices, such as the caltrop, which could be used to burst the tyres of vehicles or injure foot soldiers, Boyce and Everett, p.54 and crossbows powered by multiple rubber bands to shoot incendiary bolts.
Split into simpler sentences: SOE also revived a medieval device, the caltrop, which could be used to burst the tyres of vehicles or injure foot soldiers. SOE developed powered by multiple rubber bands to shoot incendiary bolts.