For databases that are not compatible with Endnote, and for entering details of hardcopy items you may have in your files but you cannot find references for in a database, you will need to use the manual entry feature of Endnote.
Comprehensive instructions may be found by looking in the Help file of your EndNote program under "Entering and Editing References"
An outline of how to enter data into an EndNote reference is also included in the EndNote Online User Guide - see Chapter 4: Entering a reference.
If we could just say one thing...
Back up your library!
Don't lose your work, make sure you regularly save a back-up copy of your EndNote library somewhere safe.
And don't save your "real" copy of your EndNote library on cloud storage (Dropbox, iCloud, OneDrive, etc), because the files are more likely to become corrupted. It's much safer to save your library to a hard drive.
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