Vol. 1, No. 2, April 1963 Vol. 8, No. 1, February 1970 Vol. 8, No. 2, April 1970 Vol. 8, No. 3, June 1970 Vol. 8, No. 4, August 1970 Vol. 8, No. 5, October 1970 Vol. 8, No. 6, December 1970 Vol. 9, No. 3, June 1971 Vol. 9, No. 4, August 1971 Vol. 9, No. 5, October 1971 Vol. 9, No. 6, December 1971 Vol. 10, No. 1, February 1972 Vol. 10, No. 2, April 1972 Vol. 10, No. 3, June 1972 Vol. 10, No. 4, August 1972 Vol. 10, No. 6, December 1972 Vol. 11, No. 2, April 1973 Vol. 11, No. 3, June 1973 Vol. 11, No. 4, August 1973 Vol. 11, No. 6, December 1973 Vol. 12, No. 1, February 1974 Vol. 12, No. 2, April 1974 Vol. 12, No. 3, June 1974 Vol. 12, No. 5, October 1974 Vol. 12, No. 6, December 1974