Böhlen, M. H., Jensen, C. S., & Snodgrass, R. T. Temporal statement modifiers. ACM transactions on database systems..
Cita Chicago (17th ed.)Böhlen, Michael H., Christian S. Jensen, i Richard Thomas Snodgrass. "Temporal Statement Modifiers." ACM Transactions on Database Systems. .
Cita MLA (9th ed.)Böhlen, Michael H., et al. "Temporal Statement Modifiers." ACM Transactions on Database Systems., .
Atenció: Aquestes cites poden no estar 100% correctes.