1. Trout, D.E., Gager, R.M.: Am.J.Radiol. 62, 91 (1949)
2. Zieler, Es Strahlenther. 93,579 (1954); 100, 595 (1956)
3. HPA Report B, Series No. 7
4. Authors’ measurements - Eigene Messungen - Mesures personnelles - Medidas propias
5. Wachsmann, F.: Strahlenther. 83, 41 (1950)