TY  - BOOK
ED  - Einstein Catalog Committee
TI  - Einstein observatory catalog of IPC x-ray sources: vol. 4
T2  - v.4
PY  - 1990///
CY  - Cambridge
PB  - Smithsonian Astrophysical Observatory
KW  - Catalog-Imaging propotional counter
KW  - X-Ray sources
ER  -