Volume 1
May 1970
July 1970
September 1970
November 1970
January 1971
March 1971
Volume 2
May 1971
August 1971
November 1971
February 1972
Volume 3
May 1972
August 1972
November 1972
February 1973
Volume 4
May 1973
August 1973
November 1973
February 1974
Volume 5
May 1974
August 1974
June 1975
September 1975
Volume 6
January 1976
April 1976
January 1977
May 1977
Volume 7
July 1978
May 1980
March 1981
June 1981