Thanks for posting the link here Fabio! (And thanks for visiting everyone

)
As for your question - I got my info from the Panzer Tracts series, which uses German documents from the war only. This is why they have discovered many of the flaws that originated from poor Allied intelligence, and field nicknames.
I trust this series 100%, and am yet to find something that I doubt the correctness of. You can also find much of the information in the Osprey New Vanguard books by Thomas Jentz. The New Vanguard books are a bit cheaper, but they don't cover as many vehicles as the Panzer Tracts (these should, in time, cover every German armoured vehicle...!)