Studying this subject extensively, the most books state the following:  

* **Quality Assurance: prevention activity. Act of inspection, reviewing..**  
* **Quality Control: testing**

While there are some exceptions that mention that QA deals with just processes (planning, strategy, standard application etc.) which is IMHO much closer to real QA, yet I cannot find any good reference in Google Books.

I believe that inspections, reviews, testing is all **quality control** as it is about checking products, no matter if it is the final one or work products. The problem is that so many authors do not agree.

I would be grateful for detailed explanation, ideally with a reference.