http://plato.stanford.edu/

Online Encyclopaedia of Knowledge (searchable) from Stanford University. When you enter ‘knowledge’ as a search term, you will see interesting results.

http://www.infed.org/thinkers/polanyi.htm

Information on Michael Polanyi and his conceptualization of tacit knowledge.

http://otec.uoregon.edu/data-wisdom.htm

Details on the Data/Information/Knowledge/Wisdom framework.

http://www.missouriwestern.edu/orgs/polanyi/

The Polanyi Society website, which has biographical details on Polanyi as well as an archive of his published work.

https://www.youtube.com/watch?v=iba44fxq1hQ

An interesting conversation with Nancy Dixon (author of the book titled ‘Common Knowledge) about tacit knowledge.