Several significant German-language monographs are available online (for non-commercial use) as part of the Digi20 project. They may be read and searched online or downloaded in pdf:

Hermann von Lips. Glaube—Gemeinde—Amt: Zum Verständnis der Ordination in den Pastoralbriefen. Forschungen zur Religion und Literatur des Alten und Neuen Testaments 122. Göttingen: Vandenhoeck & Ruprecht, 1979. (94MB pdf) Read more