EUVE Bowyer et al. 1996ApJS..102..129B Cat. FIRST White et al. 1997ApJ...475..479W Cat. HST_GSC Cat. HST_GSC M Cat. , star flagged as multiple IRASFSC Moshir et al. 1989 Cat. IRASPSC 1986 Cat. NED NED database NVSS Condon et al. 1998AJ....115.1693C Cat. PRI ACT98 Alcala et al. 1998A&A...330.1017A PRI AKS95 Alcala et al. 1995A&AS..114..109A Cat. PRI ATW96 Alcala et al. 1996A&AS..119....7A PRI ATZ98 Alcala et al. 1998ApJS..117..319A PRI ATZ98 Alcala et al. 1998ApJS..117..319A PRI BBD98 Boller at al. 1998A&AS..129...87B PRI BEV98 Bade et al. 1998A&AS..127..145B PRI BEV98 Bade et al. 1998A&AS..127..145B PRI BRB96 Burwitz et al. 1996A&A...310L..25B PRI BRS96 Burwitz et al. 1996A&A...305..507B PRI BSC96 Berghoefer et al. 1996A&AS..118..481B Cat. PRI BSM95 Buckley et al. 1995MNRAS.275.1028B PRI BTR98 Beuermann et al. 1999A&A...347...47B PRI CAA98 Covino et al. 1997A&A...328..187C PRI Dan98 Danner, 1998A&AS..128..331D Cat. PRI FMM95 Fleming et al. 1995ApJS...99..701F Cat. PRI FSP96 Fleming et al. 1996A&A...316..147F Cat. PRI Fle98 Fleming, 1998ApJ...504..461F PRI HSS98 Huench et al. 1999A&AS..135..319H Cat. PRI HSV98a Huench et al. 1998A&AS..127..251H Cat. PRI HSV98b Huench et al. 1998A&AS..132..155H Cat. PRI HTM94 Haberl et al. 1994A&A...291..171H PRI HWV93 Hakala et al. 1993MNRAS.263...61H PRI Has98 Hasinger, 1998 ??? PRI KMF96 Kock et al. 1996A&A...307..745K PRI KWS97 Krautter et al. 1997A&AS..123..329K Cat. PRI Koc98 Kock, 1998Thesi.........K Ph.D. Thesis, Universitat Wurzburg PRI Kun97 Kunkel, 1997Thesi.........K Ph.D. Thesis, Universitat Wurzburg PRI LKC98 Laurent-Muehleisen et al. 1998ApJS..118..127L PRI LLA95 Law-Green et al. 1995MNRAS.274..939L PRI MGH98 Motch et al. 1998A&AS..132..341M Cat. PRI MGH98 Motch et al. 1998A&AS..132..341M Cat. PRI MHD97 Motch et al. 1997A&A...323..853M PRI MHG96 Motch et al. 1996A&A...307..459M PRI MHG96 Motch et al. 1996A&A...307..459M PRI MHP97 Motch et al. 1997A&AS..122..201M Cat. PRI MMS97 Magazzu et al. 1997A&AS..124..449M Cat. PRI MPK98 Metanomski et al. 1998A&AS..131..197M Cat. PRI MWP92 Mason et al. 1992MNRAS.258..749M PRI NBK96 Nass et al. 1996A&A...309..419N PRI NSS95 Neuhaueser et al. 1995A&A...297..391N Cat. PRI NTS97 Neuhaueser et al. 1997A&A...325..647N Cat. PRI PSS96 Perlman et al. 1996ApJS..104..251P PRI RCB94 Romer et al. 1994Natur.372...75R PRI SF95 Schmitt et al. 1995ApJ...450..392S PRI SKF94 Staubert et al. 1994A&A...288..513S PRI SSK95 Stern et al. 1995ApJ...448..683S Cat. PRI Sch97 Schmitt, 1997A&A...318..215S PRI TBR98 Thomas et al. 1998A&A...335..467T Cat. PRI TBS96 Thomas et al. 1996A&A...313..833T PRI WKS96 Wichmann et al. 1996A&A...312..439W Cat. PRI WSK97 Wichmann et al. 1997A&A...326..211W PRI Wag98 Wagner 1999.in.prep....... BL Lac objects PRI Wei98 Wei et al. 1999.in.prep....... Quasars PRI XCB97 Xie et al. 1997AcApS..17..323X RITTER Ritter & Kolb 1998A&AS..129...83R Cat. ROSAT-WFC Mason et al. 1995MNRAS.274.1194M Cat. ROSATP3 ROSAT PSC pointing catalog ROSATWGA White et al. 1995 Cat. ROSATWGA 5 White et al. 1995 Cat. , something suspicious in field ROSATWGA 8 White et al. 1995 Cat. , reasonably secure detection ROSATWGA 9 White et al. 1995 Cat. , secure detection ROSHRI Cat. , Cat. ROSAT Result Archive catalogue of HRI-Pointings SIMBAD Simbad database TYCHO 1997 Cat. TYCHO D 1997 Cat. I/239/tyc_main, clear duplicity TYCHO R 1997 Cat. I/239/tyc_main, weak duplicity TYCHO S 1997 Cat. I/239/tyc_main, suspected duplicity TYCHO Y 1997 Cat. I/239/tyc_main, no duplicity found TYCHO Z 1997 Cat. I/239/tyc_main, unstudied duplicity VERONV8 Veron-Cetty & Veron 1998ESOSR..18....1V Cat.