[Skywise]

Ross Stein has done work on stress mapping, even has software available.

https://profile.usgs.gov/rstein

Following a link from the above brought me to:

http://temblor.net/earthquake-insights/

which has two articles on the Italy quakes, stress maps included.

Italy Earthquakes: Second damaging shock rips north from Amatrice

Italy Earthquakes after today’s M=6.6: What’s next?

There are more posts on the previous Italy quakes further down the page.

Brian