S. Trudinger, N. and Wang, X.-J. 2009. On the second boundary value problem for Monge-Ampère type equations and optimal transportation. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE. 8, 1 (Mar. 2009), 143-174. DOI:https://doi.org/10.2422/2036-2145.2009.1.07.