1. The Edge Flag Algorithm: A Fill Method for Raster Scan Displays;Ackland Bryan D.;IEEE Trans. Comput.,1981
2. Adobe Systems. 2008. Document management-Portable document format-Part 1: PDF 1.7. http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf Also published as ISO 32000. Adobe Systems. 2008. Document management-Portable document format-Part 1: PDF 1.7. http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf Also published as ISO 32000.
3. Graphical style towards high quality illustrations