TY - RPRT TI - A proposed performance index for galactic cosmic ray shielding materials AU - Wilson, John W. AU - Wood, J. S. AU - Shinn, Judy L. AU - Cucinotta, Francis A. AU - Nealy, John E. PY - 1993 UR - https://ntrs.nasa.gov/citations/19940006806 ID - 19940006806 ER -