Issue #495 Feb 27, 1979 Issue #496 Mar 20, 1979 Issue #497 Apr 24, 1979 Issue #498 May 22, 1979 Issue #499 Jun 19, 1979 Issue #500 Jul 17, 1979 Issue #501 Aug 21, 1979 Issue #502 Sep 25, 1979 Issue #503 Oct 23, 1979 Issue #504 Nov 20, 1979 Issue #505 Dec 18, 1979 Issue #506 Jan 22, 1980 Issue #507 Feb 26, 1980 Issue #508 Mar 25, 1980 Issue #509 Apr 22, 1980 Issue #510 May 27, 1980 Issue #511 Jun 25, 1980 Issue #512 Jul 24, 1980 Issue #513 Aug 28, 1980 Issue #514 Sep 25, 1980