Keenious is a tool that uses natural language processing "AI" to search for literature by analysing your writing. It can analyse a whole document or a selected part of a document.  Keenious has add-ons for both Microsoft Word and Google Docs.

Keenious should be used as an additional tool to search for literature along with traditional databases. It works best when you have already found some sources, done some reading and written some of your assignment. 

Keenious: https://keenious.com/

Keenious help pages: https://help.keenious.com