“…The latter consists in the search for solutions to fourth-order elliptic equations with critical exponents in the sense of the Sobolev inclusions. We refer the reader to the works by Benalili [4], Chang [8], Chang-Yang [9], Djadli-Hebey-Ledoux [10], Djadli-Malchiodi-Ould Ahmedou [12], [13], Esposito-Robert [15], Felli [16], Hebey-Robert [17], Lin [21], Robert [24], [25], to quote only few of them.…”