This report is one of the very first documents on the gross human rights violations in Cuba the first couple of months after the revolutionary government sized power in January 1959. It was published by the ICJ in August the same year. Among other things it states:
It is known from authoritative Cuba sources that 700 individuals were executed on charges of violence committed by orders of the Batista regime: murder, torture, arson, mutilation, extortion, robbery, etc. The procedure before military courts was based on the ”Law of Sierra Maestra”.
A couple of friends of mine found it in a second hand book shop in Stockholm, transcribed the foreword and published it on the Cuba Nuestra web site. I found a printed copy in my archive a couple of days ago and realized that the original page is not active anymore, so this PDF-version might still be of interest. There is a Spanish reference to it here.