Copyright Infringement?

I received an email today from Scribd, the website where I store my word documents, stating that two of my CFA study materials:

1 - Statistics - Formula Sheet Mini Test Level II
5 - Fixed Income, Derivatives, Alternatives - Formula Sheet Mini Test

have been removed as a result of a third-party notification that it holds the copyright and has not given permission for it to appear on Scribd.com.

I am confused as the material in my notes, including the formulas, are finance industry standards. How can the CFA Institute own copyrights for example over the convexity formula? Am I wrong? If I am infringing I will glady remove the material but I'm not entirely sure that I am. Does anyone have any thoughts? Much appreciated.