- http://www.adobe.com/products/acrobat/adobepdf.html
- http://www.adobe.com/devnet/pdf.html
-- http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_reference_1-7.pdf
- PDF RotatePage
-- http://www.pdf-soft.com/freesoft/free0732.html