TY  - BOOK
AU  - Hirsh Richard F
TI  - Glimpsing on invisible universe :The emeergence of x-ray astronomy
U1  - B9:(C53), M3 
PY  - 1983///
CY  - Cambridge
PB  - Cambridge university        
KW  -  Astronomy
KW  - Mathematics
N1  - Appendix p
ER  -