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: "Immerhof protected blockhouses that were constructed during a war that lasted how long?" whose answer is eight-month period.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Immerhof blockhouses war duration specific information
Useful Output:

Doc 1:  period, it was for a time occupied by several families, and at present is used for school purposes. During the Revolutionary war, it was for a short period
Doc 2: Fortress Study Group This combined history and guide to the Maginot Line is essential reading and reference for anyone interested in fortifications, especially
Doc 3: The Montmedy sector had a total length of roughly 60KM and a total of more than 70 blockhouses and 160 infantry shelters. By contrast, in 1938
Doc 4: Those killed in action fell between 1940 and 1945 and, for the most part, between 1946 and 1954. Additionally, the plan to build a cemetery was joined by the
Doc 5: Built between 1930 and 1935, Immerhof saw little action. After a renovation for continued use after World War II, the position was sold to the nearby community