http://nwcom.info/Manuale/Radio-ELECTRONIC/Specifications%20PCI-E/PCI-Express-Overview-Oct2003.pdf
http://nwcom.info/Manuale/Radio-ELECTRONIC/Specifications%20PCI-E/prod_brief[1].pdf
http://nwcom.info/Manuale/Radio-ELECTRONIC/Specifications%20PCI-E/WhatisPCIExpress.pdf