cannot read superscript,subscript and other special characters like root sign

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What steps will reproduce the problem?
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What is the expected output? What do you see instead?

Please provide any additional information below.

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Original issue reported on code.google.com by `ratnes...@trutech.org` on 27 Dec 2012 at 11:39

Attachments:
- [PhysicsDec2012.xls](https://storage.googleapis.com/google-code-attachments/php-excel-reader/issue-159/comment-0/PhysicsDec2012.xls)

Start by reproducing the issue with the attached PhysicsDec2012.xls workbook and inspect the PHP reader's handling of superscript, subscript, root signs, and other special characters. Done means those characters are read correctly from the workbook instead of being lost or misrepresented.

Written by the indexing model from the issue text.