Prevent from syncronization with online account

Greetings, dear community!

  I have a large EndNote library, but I want a set of links not to be never syncronized.

  How do I mark a set of references to prevent from syncronization with an online account?

Thank you very much!

You can’t.  You can only turn off synching to the whole library. – Maybe put those records in a second library?  You can only have one library synched per account.  

Thank you!

  This was the first thought came to my mind - to create a separate library.

  However I thought that there is a more elegant way.

  Interesting, is this possible to easily move reference between two libraries?