G. M. Wibowo, R. Rasyid, and A. H. Sulistiyadi, “Implementation of Compliance Testing Program on a Direct Digital Radiography (DDR) X-Ray System at the Radiography and Imaging Laboratory of the Health Polytechnic Ministry of Health Semarang”, LINK, vol. 10, no. 2, pp. 790–798, Aug. 2015.