Collimation of Orion Maksutov-Cassegrain Telescopes addendum
Astromania 1.25Inch Metal Collimating Cheshire Eyepiece without Laser for Newtonian Reflector Telescope - Short Version: Telescope Accessories: Amazon.com.au
How To Collimate a Telescope? A Beginner's Guide
Collimation on a Maksutov Newtonian - Reflectors - Cloudy Nights