def get_plaintext_citations(bibtex):
    """
    Parse a BibTeX file to get a clean list of plaintext citations.

    :param bibtex: Either the path to the BibTeX file or the content of a \
            BibTeX file.
    :returns:  A list of cleaned plaintext citations.
    """
    parser = BibTexParser()
    parser.customization = convert_to_unicode
    # Load the BibTeX
    if os.path.isfile(bibtex):
        with open(bibtex) as fh:
            bib_database = bibtexparser.load(fh, parser=parser)
    else:
        bib_database = bibtexparser.loads(bibtex, parser=parser)
    # Convert bibentries to plaintext
    bibentries = [bibentry_as_plaintext(bibentry)
                  for bibentry in bib_database.entries]
    # Return them
    return bibentries