2Xu D. W 1, 2 , Wei J. Y 1, 2 , Dong X. Y 1, 2 , Hu J.Y 1, 2 1 (Beijing Astronomical Observatory, The Chinese Academy of Sciences, Beijing 100012, China) 2 (National Astronomical Observatories, The Chinese Academy of Sciences, Beijing 10.High X-Ray-to-Optical Flux Ratio Sources From RASS[J].天文研究与技术,1999(S1):312-314. 被引量:1