One-handed weapons two-handed

Is there a treatise on using one handed weapons two handed? Does the second hand add to your effective strength? Does using a one handed weapon in a two handed style add damage?



Looking through the weapons lists, it seems that there are special cases where this would be true. But I haven't seen a comprehensive system for handling this.



Also, DF has rules for oversized weapons. How about for undersized ones?

One-handed weapons two-handed