@inproceedings{Hudec:2009BS, author = "Hudec, René", title = "{Very long term observations of blazars candidates for supermassive black hole binaries}", doi = "10.22323/1.063.0076", booktitle = "Proceedings of Workshop on Blazar Variability across the Electromagnetic Spectrum {\textemdash} PoS(BLAZARS2008)", year = 2009, volume = "063", pages = "076" }