Jan 1970 Vol 27 No 1Feb 1970 Vol 27 No 2Mar 1970 Vol 27 No 3Apr 1970 Vol 27 No 4May 1970 Vol 27 No 5June 1970 Vol 27 No 6July 1970 Vol 27 No 7Aug 1970 Vol 27 No 8Sept 1970 Vol 27 No 9Oct 1970 Vol 27 No 10Nov 1970 Vol 27 No 11Dec 1970 Vol 27 No 12Jan 1971 Vol 28 No 1Feb 1971 Vol 28 No 2Mar 1971 Vol 28 No 3Apr 1971 Vol 28 No 4May 1971 Volume UnknownJune 1971 Vol 29 No 6 Numbering errorJuly 1971 Vol 29 No 7Aug 1971 Vol 29 No 8Sept 1971 Vol 29 No 9Oct 1971 Vol 29 No 10Nov 1971 Vol 29 No 11Dec 1971 Vol 29 No 12Jan 1972 Vol 30 No 1Feb 1972 Vol 30 No 2Mar 1972 Vol 30 No 3Apr 1972 Vol 30 No 4May 1972 Vol 30 No 5June 1972 Vol 30 No 6July 1972 Vol 30 No 7Aug 1972 Vol 30 No 8Sept 1972 Vol 30 No 9Oct 1972 Vol 30 No 10Nov 1972 Vol 30 No 11Dec 1972 Vol 30 No 12Jan 1973 Vol 31 No 1Feb 1973 Vol 31 No 2Mar 1973 Vol 31 No 3Apr 1973 Vol 31 No 4May 1973 Vol 31 No 5June 1973 Vol 31 No 6July 1973 Vol 31 No 7Aug 1973 Vol 31 No 8Sept 1973 Vol 31 No 9Oct 1973 Vol 31 No 10Nov 1973 Vol 31 No 11Dec 1973 Vol 31 No 12Jan 1974 Vol 32 No 1Feb 1974 Vol 32 No 2Mar 1974 Vol 32 No 3Apr 1974 Vol 32 No 4May 1974 Vol 32 No 5June 1974 Vol 32 No 6July 1974 Vol 32 No 7Aug 1974 Vol 32 No 8Sept 1974 Vol 32 No 9Oct 1974 Vol 32 No 10Nov 1974 Vol 32 No 11Dec 1974 Vol 32 No 12Jan 1975 Vol 33 No 1Feb 1975 Vol 33 No 2Mar 1975 Vol 33 No 3Apr 1975 Vol 33 No 4May 1975 Vol 33 No 5June 1975 Vol 33 No 6July 1975 Vol 33 No 7Aug 1975 Vol 33 No 8Sept 1975 Vol 33 No 9Oct 1975 Vol 33 No 10Nov 1975 Vol 33 No 11Dec 1975 Vol 33 No 121976 to 1981