Left: H-, He-, and CRRLs observed with the Effelsberg 100 m telescope for α lines with principal quantum number, n, from 72 (top) to 80 (bottom) (except for W43) in steps of Δn = 1. The positions of the different lines are marked by dashed dark blue lines. The spectra are uniformly offset by 0.5 K on the T_mb. Centre: zoomed in view of the He-, and CRRL. The offsets are not uniform but varied for the ease of viewing with a typical offset of 0.2 K on the T_mb scale. Right: average He-, and CRRL profile (top) with the Gaussian fit to the He RRL presented by the dashed dark blue curve. The resulting spectrum of the CRRL is displayed below with its fit given by the dashed magenta Gaussian. For all spectra, the velocity scale is appropriate for the CRRL. The different rows (from top to bottom) present these results for W51 M, W49 N, DR21, and W43, respectively.