MARC record updates for your Ebook Central holdings are available via LibCentral.

The Ebook Central MARC Updates tool will help you track additions and removals for your subscription, owned, and DDA collections.

To access your  MARC record updates, go to LibCentral under the Collections tab, MARC Updates:
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If "MARC Updates" is not showing, it may be that your library has requested they not be shown. You can request this option by contacting Ebook Support (click the 'Submit a case' button in the upper right of any page in the support center). 

On the MARC Updates page, you'll see a line for Subscribed and/or Owned​ (all your subscriptions are grouped together. Optionally, your owned title updates can be included with the subscriptions). If you have one or more DDA profiles, they will each be listed as well (if your library has chosen to make them visible). For any of the listed MARC record sets, if new updates are available since you last downloaded your MARC records for that set, it will say "Yes". Click either the MARC record set name or Yes to proceed to the MARC page for that collection. We'll look at Subscribed and/or Owned as an example:
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The subscription and/or owned MARC page looks like this:
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Schedule and options for Subscribed and/or Owned updates only (for DDA options, please contact your Content and Workflow Consultant):
The following are the default settings. To make a change to one or more of these defaults, please contact the Technical Support Team by submitting your query on this form.
For other information about Ebook Central MARC records >See more