Papers/Books on how bitcoin works from a mathematical perspective?
www.springer.com catalog is worth checking out - technical and well respected.

Andreas Antonopolous has a book out from O'Reilly (it is also available on github).

https://bitcoin.org/en/resources - check out the Developer Guide here, it's great.

Your school library will probably have loads of journals or access to them online (eg IEEE or local equiv).

Satoshi's original whitepaper is very readable: https://bitcoin.org/bitcoin.pdf

The bitcoin wiki.