Box 53No date is provided

• If the date(s) of coverage cannot be determined but the date of the earliest (and latest if closed) records in the database can be determined, place date information in square brackets

  • REHABDATA [Internet]. Lanham (MD): National Institute on Disability and Rehabilitation Research (US), National Rehabilitation Information Center. [1956] -   [cited 2007 Feb 1]. Available from http://www.naric.com/research/rehab/default.cfm
• If the neither the date(s) of coverage nor the dates of the records in the database can be determined but the database contains a copyright date or date range, (for example: copyright 2006 by the American Chemical Society, © 2003-2007 American Medical Association, c2006 Medical College of Wisconsin), use that date preceded by "c", as c2007.

  • bioProtocol: a Bio Online Site [Internet]. Emeryville (CA): Bio.Com. c1992 -   [cited 2007 Feb 1]. Available from: http://bioprotocol.bio.com/protocolstools/index.jhtml
• If the neither the date(s) of coverage nor the dates of the records in the database can be determined nor is there a copyright date or date range, but the date can be estimated because of information found elsewhere, follow the date(s) with a question mark and place date information in square brackets

  • Nederlands Trialregister [Internet]. Amsterdam (Netherlands): Dutch Cochrane Centre. [2005?] -   [cited 2007 Feb 23]. Available from: http://www.trialregister.nl/. Dutch.
  • The Digital Database for Screening Mammography [Internet]. Tampa (FL): University of South Florida. [1999 - 2000?] [cited 2007 Feb 1]. Available from: http://marathon.csee.usf.edu/Mammography/Database.html
• If none of the above can be found, use "date unknown" in square brackets

  • Prevention Communication Research Database [Internet]. Rockville (MD): Department of Health and Human Services (US), Office of Disease Prevention and Health Promotion. [date unknown] -   [cited 2007 Feb 1]. Available from: http://www.health.gov/communication/default.asp