Microsoft is apparently doing some spring cleaning and streamlining of their different blogs, so you'll probably notice articles being removed from blogs.msdn.microsoft.com.

Some articles are moved to another blog platform over the spring, and some are just gone.

Well, not totally gone. The Wayback Machine project has been able to help me out with a couple of articles I was missing.

For example this one:
https://web.archive.org/web/20190111132925/https://blogs.msdn.microsoft.com/axmfg/2013/02/28/product-configuration-physical-data-model-for-user-selected-values/