The target resource for this PURL can no longer be traced. The following is a list of the targets this PURL was previously assigned to.
| Timestamp | Target URL | Note |
|---|---|---|
| 10/14/10 21:24:25 | http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900002786_1990002786.pdf | |
| 09/14/20 11:23:55 | https://ntrs.nasa.gov/citations/1990002786 | |
| 09/22/21 13:53:15 | https://purl.fdlp.gov/history/GPO/LPS58517 | Withdrawn from the Federal Depository Library Program, 8/2021 |