I noticed that outward links (links referring to another note) are shown as inbound links in the graph. Is there any way to reverse the direction of these links? (in the sample Carrère 2012 and Krebs have a link to Zorn 1977 and not the other way around). Looking at the manual the solution should be easy but I was unable to get it working. Any help here would be really appreciated. 
There are several variables that let you control the appearance of graphviz graphs. You are looking for org-roam-graph-edge-extra-config. To change the direction of edges (links) add ("dir" . "back") to the list:
(add-to-list 'org-roam-graph-edge-extra-config '("dir" . "back"))
Works perfect! Thanks a lot for the quick reply!
Thank you, I had been wondering about that for a long time.
Is there a reason this setting is not a default? It seems counterintuitive to me! After all, the note “Carrère” links to the note “Zorn 1977”, and not the other way around.
This exchange on GitHub might give you a clue.
My interpretation is that it’s likely because what’s intuitive is largely subjective and/or a simple implementation error (initial and/or fix).
Yes I just came across this issue. I personally think the arrows are going the wrong direction by default and so I have added the (“dir” . “back”) parameter to have them go from mentioner → mentioned.