Notes. ^(a) See Table 1 for details; ^(b)this programme is mainly focused on a long-term optical monitoring of GLQs with the LT; ^(c) no i-band data in 2014−2016; ^(d) in addition to NUV-visible-NIR data, 12 X-ray (0.1−10 keV) frames were obtained as part of a monitoring campaign with Chandra/ACIS-S3 during the first semester of 2010 (Programme: DDT#10708333); ^(e) poorer sampling in the BI bands; ^(f) IAC Gravitational Lenses Monitoring; ^(g)Gravitational Lenses International Time Project; ^(h)only a few frames in 2013−2014. All iz-band frames were taken in 2010 and early 2011; ⁽ⁱ⁾combined frames (deep imaging observations); ^(j)Spanish Service Time at the RMO; ^(k)poorer sampling in 2010, 2013 and 2014; ^(l) ~90% of frames in the r-band; ^(m) only two frames in 2015; ⁽ⁿ⁾no data in 2007−2008 in the g-band.