All partners must correctly credit the European Union's contribution to the project.
All of the details are on this page -
The correct logo to use is the Lifelong Learning Programme one (downloadable from that page)
The key phrase to use is
"This project has been funded with support from the European Commission. This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein."