Tables (or litt. reference to..) of saturated solutions of heavy
salts, like NaI2 or ZnBr2, the  densities of these solutions and their
thermal expansion coefficients

If nobody on Google Answers can find you an answer to your question
online, try to find a (book) copy of the CRC Handbook of Chemistry and
Physics.  It has data about pretty much every property of every
compound, solution, whatever you can think of.  You may be able to
find a copy of it at a local library; there is an online version, but
accessing the information requires a rather hefty subscription fee.

I recommend this as a last resort, however... the handbook is several
thousand pages long and it's sometimes difficult to navigate through
the index to find the information you're looking for.

Hopefully someone will find a website with the information you need...