How to remove this ceiling lamp cover

lamplight-fixture

I live in a dorm and my ceiling lamp died, i wanted to know how to remove this cover?
it is attached flush to the ceiling, i tried rotating it both ways and also tried pulling it, but it wont come off.
I noticed that its feels a bit springy when I pull it, but I fear i will break it if i pull it too hard.
can anyone help me??

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