“…the appendix of [20]), invoking suitable modifications of Almgren's statements (it must be noted that the construction of the center manifold occupies more than half of Almgren's monograph [11]). Based on the works [47,48,49,50,51] the author, Spadaro, and Luca Spolaor gave a complete independent proof of the existence of a branched center manifold in [53]. We also developed a suitable more general counterpart of Chang's theory in the papers [52,54,55], proving in particular the same regularity result for spherical cross-sections of area-minimizing 3-dimensional cones and for semicalibrated 2-dimensional currents (previous theorems in [12,13] proved some cases of particular interest, based on the works of Rivière and Tian, see [99,100,101]).…”