1. Christensen's physics of diagnostic radiology;Curry,1990
2. Christensen's physics of diagnostic radiology;Curry,1990
3. Diaphragm for x-ray examination in detail;Lysell;Dent Radiogr Photogr,1957
4. A cylinder cone for dental roentgenography;Manson-Hing;Oral Surg Oral Med Oral Pathol,1959
5. A new device to reduce patient irradiation and improve dental film quality;Medwedeff;Oral Surg Oral Med Oral Pathol,1962