| Covers listed | |
| 1959: | May, June, |
| 1960: | July, August, September, October, |
| 1964: | February, June, |
| 1965: | March, June, September, December, |
| 1966: | July, |
| 1967: | June, November, |
| 1970: | June, |
| 1972: | September, November, |
| 1973: | May, July, August, September, October, November, December, |
| 1974: | July, September, October, November, December, |
| 1975: | January, March, May, November, |
| 1977: | August, October, |
| 1978: | August, |
