Long-term variations of scintillation bandwidth v_d, scintillation timescale τd and DM for 13 EPTA pulsars. To ensure that the variations shown by the most precise DM values remain visible, for most pulsars, we only show the most precise DM measurements, which are usually derived from 21-cm Nançay data. The different colors indicate measurements at different telescopes, following the legend given in the top-right corner of each sub plot. Following the telescope name, we present the center frequency in units of MHz. Downward-pointing and upward-pointing triangles indicate unreliable estimates (i.e., upper and lower limits) caused by limited frequency resolution and limited observation length, respectively. The vertical gray dotted lines indicate the start of a calendar year.