We are thankful to the above named for their dedication and working on the project as YEF employees. They do not have any implied and expressed rights on this publication.
Question: Are the words " named" and "express" right? Accepting that I lack knowledge, I think they should read "names" and " expressed" rather than "named" and "express". Please help me out. Grammatical reasons will help me a lot to avoid making further mistakes.
In your original piece you had "expressed" but in your question you asked about "express". I thought you may have been so eager to get your question onto the forum that you had mistyped your question.
I would phrase your acknowledgement this way:
We thank the above named for their dedication to and work on the project as YEF employees. They do not have any implied or expressed rights in this publication.