Sources of requirements? [closed]
- by user970696
I was reading a book about SW engineering the other day and it went like:
  
    Sources of both functional and non-functional requirements are:
  
  
  
  law (for specific cases)
  business and user requirements
  etc.   //what else then?
  
So the question is, what other sources of requirements there are when an analyst is gathering the information? 
Lets consider a desktop app for mobile operator.
As for the comment, I do not think this is a broad question as the books usually mention 1-2 sources. I would like to know more, if anyone can help.