International Congress of Hedrologicum Conlegium Berlin & Hoferichter, J. (1969). Progress in proctology: Proceedings of the 3rd International Congress of Hedrologicum Conlegium, October 1968, Erlangen-Nuremberg, Germany. Springer-Verlag.
Παραπομπή σε μορφή Chicago (17η εκδ.)International Congress of Hedrologicum Conlegium Berlin και Jürgen Hoferichter. Progress in Proctology: Proceedings of the 3rd International Congress of Hedrologicum Conlegium, October 1968, Erlangen-Nuremberg, Germany. Berlin: Springer-Verlag, 1969.
Παραπομπή σε μορφή MLA (8th εκδ.)International Congress of Hedrologicum Conlegium Berlin και Jürgen Hoferichter. Progress in Proctology: Proceedings of the 3rd International Congress of Hedrologicum Conlegium, October 1968, Erlangen-Nuremberg, Germany. Springer-Verlag, 1969.
