Here's a link to a paper from Halton Arp et al. about the 'periodicity' of quasar redshifts taken from 2dF and SDSS surveys.
Periodicities of Quasar Redshifts in Large Area Surveys
Personally, I don't think he made a strong case for what he's claiming, but as you know I think his whole line of reasoning about quasars is wrong.