SORJONEN, P. On generalized resolvents of symmetric linear relations in a Pontrjagin space. Annales Fennici Mathematici, [S. l.], v. 4, n. 2, p. 365–370, 1979. DOI: 10.5186/aasfm.1978-79.0425. Disponível em: https://afm.journal.fi/article/view/134360. Acesso em: 25 nov. 2024.