There's quite a few of undercover journalistic investigations too:

>Meet The Activist Who Uncovered The Russian Troll Factory Named In The Mueller Probe

>Internet activist Lyudmila Savchuk spent two months working undercover at the troll factory in 2015

https://www.npr.org/sections/parallels/2018/03/15/594062887/... (2018)

>Inside a Ukrainian Troll Farm

>To understand how these powerful mechanisms function, OCCRP member center Slidstvo.Info sent a journalist undercover to work at a Ukrainian troll farm in advance of this summer’s parliamentary elections.

https://www.occrp.org/en/investigations/inside-a-ukrainian-t... (2019)

>Undercover reporter reveals life in a Polish troll farm

>Katarzyna Pruszkiewicz spent six months running fake social media accounts at self-described ‘ePR firm’ in Wrocław

https://www.theguardian.com/world/2019/nov/01/undercover-rep... (2019)