COMPLETE. 4 of 4.
#1 - EDGAR'S EXPERIMENTS I
At VENTOSA PENINSULA CHECKPOINT, VENTOSA PENINSULA, BARRAL.
It's inside the key-locked room (you'll get the key when capturing the checkpoint). Hanging on the wall.
#2 - EDGAR'S EXPERIMENTS II
This document is in the big villa at ISLA DEL LEON, at the top of the map.
It's on the second floor, underneath the TV.
#3 - EDGAR'S EXPERIMENTS III
It's at BIOVIDA LAB FACILITIES, OKU CREEK, BARRIAL.
It's inside the lab you had to escape from the crazy doctor in the main story.
To get back inside, enter the building at ground floor and use the staircase to get to the top.
There is a janitor's room, where you can smash the ventilation shaft entrance to get inside.
Now, the ventilation shaft is a maze. You know you're in the right place, when you reached another vent exit going up that isn't smashed yet.
Up there are two lab offices. The document is in the second one, pinned on a pinboard.
#4 - EDGAR'S EXPERIMENTS IV
This document is inside the CASTILLO NATIONAL ZOO, BALACERAS.
It's on the desk right at the main entrance.