Amazon.com: OMTech Upgraded 100W CO2 Laser Engraver Cutter 20" x 28" Laser Engraving Machine with Ruida DSP LCD Display RDWorks V8, USB Port, Air-Assist, LightBurn Software for Windows Mac OS Linux(MF2028-100)
Jarrod's Laser World: First CO2 Laser
PEV Labs - DIY Laser Project Laser Engraver
Laser CO2 Tubes, Diodes, RF and Power Supplies > Choosing Co2 tube for DIY laser
Homemade CO2 Laser Tube - YouTube
DIY CO2 Laser – Using Exhaled Air! at Buildlog.Net Blog