Volume 21, numbers 1-47; January 4, 1974; January 11, 1974; January 19, 1974; January 25, 1974; February 1, 1974; February 8, 1974; February 15, 1974; February 22, 1974; March 1, 1974; March 8, 1974; March 15, 1974; March 22, 1974; March 29, 1974;...
Volume 19, numbers 1-49; January 7, 1972; January 14, 1972; January 21, 1972; February 4, 1972; February 11, 1972; February 18, 1972; February 25, 1972; March 3, 1972; March 10, 1972; March 17, 1972; March 24, 1972; March 31, 1972; April 7, 1972;...
Volume 20, numbers 1-50; January 5, 1973; January 12, 1973; January 19, 1973; January 26, 1973; February 2, 1973; February 9, 1973; February 16, 1973; February 23, 1973; March 2, 1973; March 9, 1973; March 16, 1973; March 23, 1973; March 30, 1973;...