def apply_filter(d, fos, y):
    """
    This function is used to apply all the useful filers
    :param y: year
    :param d: jason as a dictionary
    :param fos: field of study
    :return: the result of the filer
    """
    if "paperAbstract" in d.keys() and \
            "title" in d.keys() and \
            "fieldsOfStudy" in d.keys() and \
            "sources" in d.keys() and \
            "year" in d.keys():
        return len(d["paperAbstract"]) > 0 and "DBLP" in d["sources"] and fos in d["fieldsOfStudy"] and d["year"] > y

    return False