https://plato.stanford.edu

Stanford University’s Online Encyclopaedia of Philosophy (searchable).

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.knowledge-management-tools.net/different-types-of-knowledge.html

The KMT A to Z of knowledge.

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.