i'm sorry for asking this but i'm so curious about this.. do examiner really read our thesis and all sources inside our references ? thanks

They will read your thesis in detail. They are highly unlikely to be looking at your references.

However, if they know your field inside out, they don't need to look at your references - they will likely know the work just as well as you do and so will know whether you've used the "correct" references or not.

In the humanities, some examiners (at least 2 that I know of) do begin by reading abstract, intro, then scanning the bibliography before reading through the entire thesis. They said it gives them an idea of how your orientate your work, and as Tree said, if you've hit all the 'correct' references.