Where is the source code for the Prestashop backend stock management page?

[vav_]

Hi everyone ! 

I'm a developer apprentice and I've been asked to find a way to modify items in the stock page.
What is the tree structure to get to the view page? 
At the same time, where is the customer email alert function?
Because I would like to study the structure of the function to reuse it. 

Regards.