@Misc{ CaMaMoPu18, author = { Catino, Giovanni and Mastrolia, Paolo and Monticelli, Dario Daniele and Punzo, Fabio }, title = { Four dimensional closed manifolds admit a weak harmonic Weyl metric }, journal = { Comm. Cont. Math. }, year = { 2022 }, pages = { }, URL = { http://cvgmt.sns.it/paper/4075/ }, note = { cvgmt preprint} }