@ARTICLE{
author={Shapovalova Alla I,Popovic Luka C,Chavushyan Vahram H,Burenkov Alexander N,Ilic Dragana J,Kollatschny Wolfram,Kovacevic Andjelka B,Valdes JR,Patino-Alvarez V,Leon-Tavares J,Torrealba J,Zhdanova VE},
year={2016},
title={First Long-Term Optical Spectral Monitoring of a Binary Black Hole Candidate E1821+643. I. Variability of Spectral Lines and Continuum},
journal={ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES},
volume={222},
number={2},
pages={-},
document_type={Article},
} 

@ARTICLE{
author={Popovic Luka C,Shapovalova Alla I,Ilic Dragana J,Burenkov Alexander N,Chavushyan Vahram H,Kollatschny Wolfram,Kovacevic Andjelka B,Valdes JR,Leon-Tavares J,Bochkarev Nikolai G,Patino-Alvarez V,Torrealba J},
year={2014},
title={Spectral optical monitoring of the double-peaked emission line AGN Arp 102B II. Variability of the broad line properties},
journal={ASTRONOMY & ASTROPHYSICS},
volume={572},
number={},
pages={-},
document_type={Article},
} 

@ARTICLE{
author={Shapovalova Alla I,Popovic Luka C,Burenkov Alexander N,Chavushyan Vahram H,Ilic Dragana J,Kovacevic Andjelka B,Kollatschny Wolfram,Kovacevic Jelena M,Bochkarev Nikolay G,Valdes JR,Torrealba J,Leon-Tavares J,Mercado Abelardo,Benitez E,Carrasco L,Dultzin D,de la Fuente E},
year={2012},
title={Spectral Optical Monitoring of the Narrow-Line Seyfert 1 Galaxy Ark 564},
journal={ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES},
volume={202},
number={1},
pages={-},
document_type={Article},
}