first names appearing in some citations

Hi, Sometimes when I insert a citation in my Word document the initials of the first name appear even though they shouldn't. I cross-checked many times and for some other authors entered exactly the same way in my database 9same spacing, same coma, same dots), the initials do not appear. (and they are not entered as "institution/organization", I checked that as well) There was already a question posted about that entitled "first names added to some citations" on Feb 12 2013 but it did not help me to fix it. Do you know how to change that? Thanks