Squared visibilities with error bars, expected photospheric squared visibility (blue shaded region) and best-fit star-disc model (solid line) with its 3σ confidence interval (dotted lines), plotted as a function of hour angle for all the targets not already presented in Paper I or Paper II. The best-fit disc/star contrast is given as an inset, together with the reduced χ² of the fit. The two error bars given on the disc/star contrast correspond to the statistical and systematic errors (see Sect. 4.1). Also given is the mean limb-darkened angular diameter used in the oblate photospheric model. The position angle (PA) of the oblate apparent photosphere is generally not known. This uncertainty is taken into account in the width of the blue line, except in the cases where the PA is known from previous studies (it is then specified in the inset). Different symbols are used for data taken in different years: circles (2006), upward triangles (2007), downward triangles (2008), squares (2009), diamonds (2010), and crosses (2011).