References
- Dennis, A. A. (1944) A rotating indicator. Radiography, 10, p. 46.
- Mattsson, O. (1952) Aspects of the interpretation of contrast and detail of radiographs. Acta radiol, 38, p. 477.
- Mattsson, O. (1953) A magnifying viewer for photofluorographic films. Acta radiol, 39, p. 412.
- Mattsson, O. (1953) A simple centering device for radiographic tubes. Acta radiol, 40, p. 27.
- Watson, W. (1942) Telescopic centering device. Radiography, 8, p. 7.
- Willner, O. (1953) A time-marker for urograms. Acta radiol, 39, p. 499.