1991
January/February 1991; 53 (1): 1 - 117	March/April 1991; 53 (2): 119 - 198	May/June 1991; 53 (3): 247 - 340
July/August 1991; 53 (4): 345 - 462	September/October 1991; 53 (5): 467 - 584	November/December 1991; 53 (6): 587 - 712