Just the legal and constitutional ones - factual article from the point of view of a constitutional expert.
ukconstitutionallaw.org/2016/06/22/alan-renwick-the-road-to-brexit/
Puts to rest some of the nonsense spouted by both sides, such as Cameron being gone in days (not constitutionally possible).
The most concerning thing for me is the amount of legislation that would need to be passed in a short space of time, and how unprepared Whitehall would be after the cuts of the last few years.