Goldman, M., and B. Merlet. “Non-Convex Functionals Penalizing Simultaneous Oscillations Along Independent Directions: Rigidity Estimates”. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, vol. 22, no. 3, Sept. 2021, pp. 1473-09, doi:10.2422/2036-2145.201906_006.