def get_all_references_from_aux(aux_file_path):
    """
    Determine citation keys from aux file.

    :param aux_file_path:
        The path of the aux file.
    :return:
    [str]
        The list of all citation keys.
    """
    all_references = set()
    with open(aux_file_path, "r") as aux_file:
        for line in aux_file:
            if line.startswith("\\abx@aux@cite") or line.startswith("\\citation"):
                reference = line.strip().replace("\\abx@aux@cite{", "").replace("\\citation{", "").replace("}", "")
                for one_reference in reference.split(","):
                    all_references.add(one_reference)
    return all_references