The "An" and "RAR" suffix could point toward biological research into Retinoic Acid Receptors [1]. Detailed papers on this topic cover the structural and physiological effects of RARs and their cooperation with retinoid X receptors (RXRs).
"RAR" also stands for the Relationships Among Rivals framework used in political science and process-tracing research [2]. Where to Find the Actual Paper
: Often hosts self-archived papers and datasets from individual researchers [3].
The "Uk" prefix often refers to the United Kingdom. It may contain policy papers or reports similar to those found on GOV.UK , such as those from the UK Covid-19 Inquiry [4].