The Five Stages of Culture Shock: Critical Incidents Around the World by Paul Pedersen is a good reference for the early approaches to culture shock. I particularly like the history of the U- and W- curves. These visual aids are given to most students in their per-orientation programs before they travel abroad. I know I received one before I attended a fieldschool in Portugal. The book notes that one criticism of these curves are their linear depictions of assimilation. I would be curious to see if, having been introduced to stage models such as these before traveling, students feel an increase in the magnitude of culture shock for not matching the model.