References
- Kirsch , M. , Tapphorn , R. M. , Beeson , H. D. and Benz , F. J. ( 1991 ) ‘ Investigation of Nondestructive Evaluation Methods to Determine the Integrity of the Arm Pivot Inserts in the Shuttle Extravehicular Mobility Unit ’, TR- 667 – 001 , NASA Johnson Space Center, White Sands Test Facility , Las Cruces , NM .
- ASTM E-545–86 . ( 1986 ) ‘ Standard Method for Determining Image Quality in Direct Thermal Neutron Radiography Examination ’, American Society of Testing Materials .
- Lewis , D. L. , Clinton , L. M. ,and Mark , G. R. ,‘ Continuum X-ray Gauging of Multiple-Element Materials ’, Spectroscopy , Vol. 7 , No. 3 , March/April 1992 pp. 40 – 48 .