I'm beginning a research on the different approaches to QG (or also calssical QM) where the attempt to introduce the notion of spacetime as an emergent concept is made. I would like to find for introductory material which describes in one (or few) papers these different approaches giving first an overview on the subject. Can anyone suggest some? If there is none, please suggest the approaches/theories/ speculations (in string theory, CQG, or even alternative theories) you believe are actually the most interesting/promising in potentially describing physics where space and time no longer is a foundation but only a low energy emerging property. Thank you, Mark.