questions , thank you

[minhua]

"I am a project management trainer and consultant. PMP Prep is one of the classes I teach and I can say: ‘Move over Rita and ESI.’ Kim's book rivals these staples of PMP Prep. I will use this book in my courses."
What does “‘Move over Rita and ESI.’ Kim's book rivals these staples of PMP Prep.” mean here?

 

[Tdol]

A 'staple' is a standard text used by almost everyone. This text suggests that the new books are better than the standard ones, written by Rita and ESI.;-)