Hello everyone!

During my research about Crossbows, I often read about the wooden crossbows ,which were for example used by the early crusaders, but never found pictures (drawings etc.) or detailed descriptions on how these bows worked (release mechanism etc.) which average size they had and how the prod looked like (did it have a D-like cross-section or was it square, were the tips recurved or reinforced in some way, how high was the draw-weight)....
So my question is, if someone has the knowledge, pictures or usable descriptions to tell me about those things.

Thanks in advance