Pasquarello, AlfredoQuattropani, A.2009-10-082009-10-082009-10-08199110.1016/0749-6036(91)90273-Thttps://infoscience.epfl.ch/handle/20.500.14299/43346WOS:A1991FD40200005Excitonic Effects on the 2-Photon Transition Rate in Quantum-Wellstext::journal::journal article::research article