The long-term variability of BL Lac object PKS 0735+178 J. H. Fan, G. Z. Xie, R. G. Lin, Y. P. Qin, K. H. Li and X. Zhang Astron. Astrophys. Suppl. Ser., 125 3 (1997) 525-528 Published online: 15 November 1997 DOI: 10.1051/aas:1997240