Celestron 127EQ PowerSeeker Review - Not Recommended
Hobby Killers: What Telescopes Not to Buy - Sky & Telescope - Sky & Telescope
Celestron NexStar Evolution 9.25 review – Astronomy Now
Amazon.com : Meade Instruments – Polaris 90mm Aperture, Portable Backyard Refracting Astronomy Telescope for Beginners –Stable German Equatorial (GEM) Manual Mount – Accessories Included – Outdoors Family Fun : Electronics
Super-pressure Balloon-borne Imaging Telescope - Wikipedia
Bresser Messier AR-80/640 Nano refractor review - BBC Sky at Night Magazine
OptiTest® - Visual optical measurement instruments by TRIOPTICS US
Baader Domes / Baader Planetarium Blog Posts
ATUS | Institute of Space Systems | University of Stuttgart