Google's in-depth articles just got an update. Google announced it on Google+ highlighting two new features.
(1) A link under the 3 in-depth articles to show more in-depth articles
(2) Explore links to other topics and queries that will show more search results that contain in-depth articles.
Here is a picture of a search for [federal reserve] that shows these two features:
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Rubén Gómez documented how to search Google' in-depth articles with a URL parameter addition. Specifically adding &ida_m=1 to the end of your search URL.
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(1) A link under the 3 in-depth articles to show more in-depth articles
(2) Explore links to other topics and queries that will show more search results that contain in-depth articles.
Here is a picture of a search for [federal reserve] that shows these two features:

Rubén Gómez documented how to search Google' in-depth articles with a URL parameter addition. Specifically adding &ida_m=1 to the end of your search URL.
Read More>>