April 15-May 1, 1981	May 2-15, 1981	May 16-31, 1981
June 12-July 2, 1981	July 3-July 19, 1981	July 20-July 31, 1981
August 1-31, 1981	September 1-7, 1981	September 8-13, 1981
September 25-October 12, 1981	October 17-25, 1981