Lessons of the Events in Dublin - Leon Trotsky's view on the 1916 Easter Uprising in Ireland. - http://www.marxists.org/archive/trotsky/works/1916/dublin.htm
In Defence of the Russian Revolution - Written by Trotsky, this article includes a useful summary of his theory of uneven and combined development. - http://www.marxist.com/History/copenhagen.html
What is the theory of the Permanent Revolution? - An essay on Trotsky's theory concerning the revolutionary dynamic, particularly as it effects underdeveloped countries. - http://www.trotsky.net/trotsky_year/permanent_revolution.html