Silk.co is a free database where people create accounts on narrow subjects.
Where do I find details about a topic I am writing about?
For instance, one person created a database with information on the 1551 known volcanoes in the world, with pictures, from other public databases.
So, it is easier to find a dedicated source for a topic, rather than a google search which may place the Silk.co account many levels deep on the search list.
Try it when you need some details or statistics about a topic.
Authors' Roundtable of Mount Dora, FL 