generating two references
I am having a problem with my reference list and citations. I switched from Mendeley to Zotero and when placing my citation within my paper they are generating two references. For example, when I use the citation (Bass and Riggio, 2006), it comes up as (Bass and Riggio, 2006a) and (Bass and Riggio, 2006b). They are the same references and then the reference list populates it with the two references. How do I eliminate one of the references and citations?