SWIFT-community.

NACHA - The Electronic payments Assocition 

PayItGreen
-Experience the vision - video

PayItGeen - Good for the environment. Good for You.

EU commission initiative on e-invoicing

Status report from the Expert Group on E-invoicing

Haq, S. (2007) Electronic Invoicing Gains as Adoption Barriers Fall. Financial Executive, Sep2007, vol. 23, iss. 7.