Bibtex help

Hey folks. I've just (finally) started using Bibtex. I've got it figured out for the most part, but there's one thing bugging me: all my citations include a bunch of extraneous information, e.g., ISBN, ISSN, and so on.

Different citation styles seem to have the same problem (though I've not tried them all). Has anyone encountered this? I'm using zotero with LyZ to generate the Bibtex file. Is that a mistake? Any help would be greatly appreciated.