no. 1 - March 1971

no. 2 - May 1971

no. 3 - July 1971

no. 6 - December 1971

no. 7 - February 1972

no. 10 - August 1972

no. 11 - December 1972

no. 12 - March 1973

no. 15 - July 1973

no. 17 - October 1973

no. 18 - November 1973

no. 19 - December 1973