- 1986 to 19875
- 1988 to 19892
- 1990 to 19910
- 1992 to 19930
- 1994 to 19951
- 1996 to 199714
- 1998 to 19990
- 2000 to 200111
- 20022
The preservation of the Duke University Libraries Digital Collections and the Duke Digital Repository programs are supported in part by the Lowell and Eileen Aptman Digital Preservation Fund