It's mentioned here and there. But you're right, there's not a dedicated article.
I'll add that to the to-do list:
http://www.digitalFAQ.com/forum/show...-web-2468.html
Most of that data is located in white papers and patent documents.
For example,
http://www.sinoimpex.com/araldite/DV...gCoreRange.pdf (also attached to this post)
Or
http://www.xenoncorp.com/Literature/PDF/DVD_Bro.pdf (also attached to this post)
The various materials are purchased by manufacturers and then used for their production lines (or their production lines as overseen by third parties).
It always comes back to the quality of materials. Cheap discs are well known for flaws like this. However, better media will use better materials. That is not to say that good discs will sometimes not be hampered by bad product. That's where real "bad batches" (tens of thousands of discs) come from. Even Taiyo Yuden and Mitsubishi have had to deal with this in the past. I'm not surprised that Prodisc had an issue, even with them being one of the better manufacturers.
Remember that end-user storage and handling can play into this, too. If you have a lot of issues, I'd question your humidity/location, as well as the cases used for the discs. Pressure from crappy cases are known to both crack media and stress the bonding enough to split discs. That includes "name brand" cases like AlphaPak, too!