To save citations to your My NCBI account, first be sure you're logged in. Select any articles you wish to save by clicking the checkbox to the left of the title.
From there you'll need to  Click Send to and select  My Bibliography. Select  My Bibliography from the second box and hit  Add to Bibliography. This will send the citations for the articles you've selected to your My NCBI Bibliography.
To access your Bibliography, click on My NCBI in the upper right side of your screen.
To get your citations into Zotero, follow these steps:
To get your citations into EndNote: