'Endnote find and insert my reference' is not finding my saved references

I am using the inset citation tool in Word but for many of my references it is not locating the articles that are saved in my Endnote groups? I have tried authors names and titles of articles but neither seems to work for certain articles. Help!

Just first make sure you are using the tool on the References Ribbon which is the Word citation tool.  You should be using the tools on the EndnoteX7 ribbon?  

BUT I actually never use that.  I use it to go to the endnote library, find and select the needed records and then use the endnote program tool to “insert citation” (curved down red arrow on document).  This jumps back to the word document and inserts (and formats - - if instant formating is on) the citation.  I find the search tools much better from within endnote (field specific) as opposed to the insert citation dialog which has no filters on fields capabilities.