I did my master thesis searching for anysotropies of the CMB (Cosmic Microwave Background)., before they were actually dicovered by COBE etc. Some of the original plots of the thesis are in this paper by Lasemby et al. (1987), which is the first one in the series of papers on the Tenerife experiment.
I also did some work spectral line formation in the CMB It was proposed-stirred by R. Rebolo. He asked me why the CMB does not have spectral lines, despite the fact that there is a gradient of temperature along the line of sight, and a gradient of opacity with wavelength within a line. (These are the two ingredients responsible for the formation of lines in stellar atmospheres.) This is the little paper that came up out of those months of work.