def get_plaintext_citations(bbl):
    """
    Parse a ``*.bbl`` file to get a clean list of plaintext citations.

    :param bbl: Either the path to the .bbl file or the content of a ``.bbl`` \
            file.
    :returns:  A list of cleaned plaintext citations.
    """
    # Handle path or content
    if os.path.isfile(bbl):
        with open(bbl, 'r') as fh:
            bbl_content = fh.read()
    else:
        bbl_content = bbl
    # Get a list of bibitems, taking the first item out as it is *before* the
    # first \bibitem
    bibitems = BIBITEMS_REGEX.split(bbl_content)[1:]
    # Delete the text after the \end{thebibliography}
    bibitems = [ENDTHEBIBLIOGRAPHY_REGEX.sub("", i).strip() for i in bibitems]
    # Clean every bibitem to have plaintext
    cleaned_bbl = [bibitem_as_plaintext(bibitem) for bibitem in bibitems]
    return cleaned_bbl