...
机译:Spectral variability of quasars from multi-epoch photometric data in the sloan digital sky survey stripe 82
Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany;
Astronomisches Institut, Universit?t Bern, Sidlerstra?e 5, 3012 Bern, Switzerland;
Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany;
galaxies: active; quasars: emission lines; quasars: general;