Here is an interesting article by Gabino Ponce Herrero on the evolution of the urban planning context in Havana during the first half of the XXth century. It is also the story of the eastern urban extension project, first thought as a private development linked to the new tunnel under the bay, and later developed under the socialist regime in a different way. The economic evolution of the country has made of what was to be a model (and would today probably seem a common social housing project in most of Europe) just an isolated work.