| ! | Part of this article was copied from Citizendium but the copied text was originally written by me, RJJensen (under the name Richard Jensen) and does not include major contributions made by others on that site. | 
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| ! | Part of this article was copied from Citizendium but the copied text was originally written by me, RJJensen (under the name Richard Jensen) and does not include major contributions made by others on that site. |
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