def fix_month(bib_str: str) -> str:
    """Fixes the string formatting in a bibtex entry"""
    return (
        bib_str.replace("{Jan}", "jan")
        .replace("{jan}", "jan")
        .replace("{Feb}", "feb")
        .replace("{feb}", "feb")
        .replace("{Mar}", "mar")
        .replace("{mar}", "mar")
        .replace("{Apr}", "apr")
        .replace("{apr}", "apr")
        .replace("{May}", "may")
        .replace("{may}", "may")
        .replace("{Jun}", "jun")
        .replace("{jun}", "jun")
        .replace("{Jul}", "jul")
        .replace("{jul}", "jul")
        .replace("{Aug}", "aug")
        .replace("{aug}", "aug")
        .replace("{Sep}", "sep")
        .replace("{sep}", "sep")
        .replace("{Oct}", "oct")
        .replace("{oct}", "oct")
        .replace("{Nov}", "nov")
        .replace("{nov}", "nov")
        .replace("{Dec}", "dec")
        .replace("{dec}", "dec")
    )