1991
January January; 22 (1): 1 - 109	February February; 22 (2): 155 - 284	March March; 22 (3): 299 - 416
April April; 22 (4): 431 - 535	May May; 22 (5): 571 - 695	June June; 22 (6): 711 - 820
July July; 22 (7): 835 - 956	August August; 22 (8): 971 - 1090	September September; 22 (9): 1105 - 1214
October October; 22 (10): 1229 - 1330	November November; 22 (11): 1345 - 1467	December December; 22 (12): 1485 - 1609