The palaeography of Mycenaean iniscribed sealings from Thebes and Pylos, their place within the Mycenaean administrative system and their links with the extra-palatial sphere - Palaima, T.G (Minoisch-mykenische Glyptik. Stil, Ikonographie, Funktion. V. Internationales Siegel-Symposium, Marburg 23. - 25. September 1999)