Some good examples to a body of work that is a typology would be Bernd and Hilla Becher's Water Towers, and perhaps August Sander's portraits. Essentially, a study of one thing photographed in several different contexts. In the case of the Becher's they went out of their way to photograph the water towers in similar flat light all over Europe. (Actually... I'm not entirely sure they are all in Europe)

In the case of Sander... he was studying a society of people, and though he wasn't making pictures in quite the same way as the Becher's as their is some variety in how he photographed each sitter, but taken as a whole... it is a study of a "type"

I hope I explained that well... anyone else want to jump in?