Where can i find the receipes for the important alchemical potions ?

[Norbert Irmer <norbert.irmer@heim9.tu-clausthal.de>]

Hello,

I would like to ask if it's possible to get the
alchemical receipes for every important potion in the
game in a legal way ?

I am asking this because I am currently trying to get the receipe
for fire (and cold) resistance in the Volcano research center,
and I must say that the idea of getting important alchemical receipts
at the end of a difficult quest is highly motivating.

(But the Balrog/Greater Demons at the end of the research center quest
have attack type poison, so that my tactic of drinking every immunity
potion and then frontal assault doesn't works for them,
since there is no potion which grants immunity to poison.
So I am now trying to get the Venomtooth of something from the
Snake pit first, since it grants immunity to poison as I read
in the spoiler)

But I would like to now if it's possible to get the other receipts
for shock immunity and invulnerability somewhere else too (and where ?
- i couldn't find any hints about this in the spoiler on the real-time
site :) 

Norbert