1. Problems of designing of optico-electronic systems for determination of a mutual position in the space of objects or their elements;Andreev,1995
2. “Unified Line of Digital Two-Dimensional Autocollimators OPTRO-AK,” OPTROTECH, http://www.optrotech.ru/eng/prod1-4-eng.php (24 December 2015)
3. “Electronic Autocollimators,” MÖLLER-WEDEL OPTICAL GmbH, http://www.moeller-wedel-optical.com/en/produkte/electronic-autocollimators.html (24 December 2015)
4. “Ultra High Precision Dual Axis Digital Autocollimator,” Taylor Hobson, http://www.taylor-hobson.com/products/25/110.html#Ultra-Dual-Axis-Digital-Autocollimator2 (24 December 2015)
5. A universal angle-measuring instrument