def handle033a(tokens):
    """
    Processes the 033A (Ort und Verlag) field. Currently, only subfield p and n are supported.
    For details (in German), see: https://www.gbv.de/bibliotheken/verbundbibliotheken/02Verbund/01Erschliessung/02Richtlinien/01KatRicht/4030.pdf
    :param tokens: a list of tokens of the field 033A
    :return: a tuple in form of (<publisher>,<place(s)>)
    """
    ort=""
    verlag=""
    for token in tokens:
        if token.startswith("p"):
            ort=token[1:].replace("@","").strip()
        elif token.startswith("n"):
            verlag=token[1:].replace("@","").strip()

    return((verlag,ort))