You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "who created the demographic transition model (dtm)?" whose answer is American demographer Warren Thompson.
Each document should contain about 30 words, and these documents should contain useful information.

Query: creation of demographic transition model
Useful Output:

Doc 1: The demographic transition model was built based on patterns observed in European counties as they were going through industrialization. This
Doc 2: Demographic transition is a sociological model based on the idea that birth and death rates correlate with stages of industrial development.
Doc 3: Having originated in the middle of the 20th century, the demographic transition model is now over half a century old. It is the product of
Doc 4: The Demographic Transition Model (DTM) as developed by demographer Warren Thompson in 1929, depicts the transition of a country from high birth-
Doc 5: More from Heimler's History: ***AP Human Geography Heimler Review Guide: https://bit.ly/3XEc6Bu ***AP Human Geography Video NOTEGUIDES Units