Hi Michelle,
Well, I hope your German language skills are reasonable...
Check out:
Steinfartz, S. 1995. Zur Fortpflanzungsbiologie von Neurergus crocatus und Neurergus strauchii barani. - Salamandra, 31: 15-33
Steinfartz, S. 1997. Die Gattung Neurergus. Faszinierende Bergbachsalamander aus dem Nahen Osten. - Reptilia (Muenster, Germany), 2: 43-48 [nice review]
Max Sparreboom, M., S. Steinfartz & G. Schultschik. 2000. Courtship behaviour of Neurergus (Caudata: Salamandridae). - Amphibia-Reptilia, 21: 1-12
The person you want to talk to is definitely Henk Wallays - he breeds them and can give you a lead if you have any special questions.
BTW, Henk, I'll sponsor a tight lid for your crocatus tank if this is of any help...
Also contact Guenter Schultschik who manages a studbook for N. crocatus and has all published literature on this species available.
BTW, are the GPZ's specimens adult?
Best wishes,
kai