This isn't the original source, but useful nonetheless. If you download this pdf from the Connected Cities site:
Legislation
and then click the first index item, you'll see the E-bike and pedelec legislation in the EU.
Scroll down a bit to "legal status of e-bike" and you'll see that member states are free to make their own rules regarding insurance, age limit, helmet, so much more freedom than is commonly supposed.
Lots more information there, including the fact that only the UK and Sweden have the ridiculous lower age limit on pedelecs, children elsewhere able to ride them as they should in my view. Belgium have a unique 300 watt motor rating too!
The connected cities site is linked from the Croydon Cycling Campaign, and heres the link:
Connected Cities
.