Additional marriage contracts:
The National Library of Israel holds a large collection of Jewish marriage contracts. The ketubbot are divided based on rite: Sephardic, Ashkenazic, Italian, Yemenite, and more.
The Stroum Center for Jewish Studies at the University of Washington collects marriage contracts from the Sephardic diaspora.
This marriage contract in the holdings of the Jewish Museum in New York is from Persia.
Columbia University's collections of Ketubbot from Corfu is available here.
Orly C. Meron, “The Marriage Contracts of Portuguese Jews from Bayonne, 1721–1816: Migration, Sub-Ethnicity, Gender, and Economics," Hamsa: Journal of Judaic and Islamic Studies https://journals.openedition.org/hamsa/771
Jessica V. Roitman, "Marriage, migration, and money: the Santa Companhia de dotar orphas e donzelas pobres in the Portuguese Sephardic Diaspora," Portuguese Studies Review 13, no. 1-2 (Jan.-July 2005): 347--
Joannis Seldeni, Uxor Ebraica (Francofurti ad Oderam [i.e. Frankfurt a.O.] : Sumptibus Jeremiae Schrey, excudit Joh. Mich. Goderitsch, 1695). John Selden's work from 1695, focuses on the Jewish law of marriage. A copy from the 1695 edition is accessible in Pitts library. A digitized version is available from Hathitrust.org.