Hi, why you want to recover your university exam data. If you previously backup your Mac using Time Machine/online backup storage, then just restore it and regain access to lost or deleted files.
However, if you have done some laziness and do not have a proper backup available, then there are no other options left other than using a data recovery software for Mac. You can use Stellar Phoenix Mac Data Recovery Application Program to retrieve all the deleted files back to the hard drive. This software for data recovery supports more than 500+ file types for data retrieval.
Also, data rescue is a good software but its features are limited like Time Machine recovery, RAW recovery, BootCamp partition recovery.