[cherry]

https://en.wikipedia.org/wiki/Lead(II)_iodide
Wikipedia lists the solubility constant of lead(II) iodide as 4.41×10−9 at 20 °C, but I cannot find any source cited to back this up. I want to use this value because I'm conducting an experiment at that temperature and need to know what to cite. Can someone help me verify whether this is indeed from a valid source?

[Borek]

Handbook of chemical equilibria in analytical chemistry (Kotrlý & Šůcha, Ellis Horwood Ltd. 1985) lists pK_sp of PbI₂ as 8.1 at ionic strength 0, and 7.61 at ionic strength 2.0.

It further gives R.M.Smith and A.E.Martell, Critical Stability Constants, Vol. 4 Plenum Press, New York, 1976, as a reference for this value.