“…There is now an extensive literature about this problem, we refer to Adimurthi et al [1], Baraket et al [3], Clapp et al [9], Druet and Robert [10], Hebey and Robert [11], Hebey et al [12], Malchiodi [20], Robert and Wei [24] and the references therein. In particular, we mention the two papers [3,9], where they constructed m-point blowing-up solutions for…”