Read their TOS
You are full responsible for any copyright problems.
If you upload anything on studocu.com that is not your text, not your image or whatever, you are at risk getting sued.
Studoc is not responsible:
Terms of service from their website:
5.6 If you upload Study Material to the Platform, you guarantee that:
You are the full right holder with regard to the study material and you are entitled to upload it to the Platform and offer it to other users;
The Intellectual Property Rights, including the copyright, to the Study Material is vested in you or you have demonstrable consent of the party in which the Intellectual Property Rights are vested to upload the Study Material to the Platform and to offer it to other users;
The Study Material is not in violation of any laws or legislation and/or does not infringe on any (Intellectual Property) Rights of third parties and/or is not otherwise unlawful towards third parties and/or StuDocu.com;
StuDocu.com will not be held to make any payments in relation to the uploading and use of the Study Material; and
You are exclusively responsible for all licenses and payment obligations to any third party relating to the uploading and use of the Study Material.