The "Geschichte der hethitischen Religion" is the first representation of a comprehensive history of the Hittite Religion from the beginning of the Neolithic until the end of the era of the Hittite Great Kingdom, giving insight in until now for the most part unknown sources.

'..".standard reference work'
M.S.S. "Old Testament Abstracts, 1995.
'..".the work contains a wealth of information, with a solid critical apparatus. It will be an indispensable tool for every student of Ancient Middle Eastern religion and for a better understanding of the Hittite gods and cult and their outside relationships.'
Edgar C. Polomi, "The Journal of Indo-Euopean Studies.
'"The wealth of material, the depth of the analysis and the clarity of the presentation make V. Haas's book an indispensable tool not only in the sphere of Hittitology, but also in that of te History of Religions.'
Stefano de Martino, "Bibliotheca Orientalis, 1997.
'..". brings together a very impressive amount of information, with Haas's interpretation, in one place. This will be an extremely useful work for reading up a particular cultic tradition or festival and especially for quickly reminding oneself of the textual evidence and secondary literature on any aspect of Hittite religion. The sheer volume of work involved is impressive; its strength lies in its comprehensiveness and accessibility. Specialists and non-specialists alike will gladly use it as their standard reference on Hittite religion.'
Gregory McMahon, "Newsletter for Anatolian Studies, 1996.