Chinchusak, Wanchai, Vittaya Tipsuwanaporn, and Pochaman Tagheen. 2018. “A New Calibration Technique for Autocollimator by using a Small Angle Generator and Laser Interferometer”. CURRENT APPLIED SCIENCE AND TECHNOLOGY 1 (1). Bangkok, Thailand:146-49. https://li01.tci-thaijo.org/index.php/cast/article/view/153181.