Number | Name | Date | Kind |
---|---|---|---|
3615298 | Benson | Oct 1971 | |
3640336 | Dixon | Feb 1972 | |
3734184 | Scott | May 1973 | |
3805885 | Huisen | Apr 1974 | |
3858397 | Jacoby | Jan 1975 | |
3967675 | Georgu | Jul 1976 |
Entry |
---|
"This Changing Earth", Matthews, National Geographic, Jan. 1973, pp. 1, 5, 26. |
McGraw-Hill Encyclopedia of Science & Technology, vol. 14, pp. 404-409, 1971. |