1991
January January; 29 (1): 1 - 226	February February; 29 (2): 227 - i4	March March; 29 (3): 419 - 666
April April; 29 (4): 667 - 852	May May; 29 (5): 853 - 1087	June June; 29 (6): 1089 - 1280
July July; 29 (7): 1281 - 1557	August August; 29 (8): 1559 - 1756	September September; 29 (9): 1757 - 2092
October October; 29 (10): 2093 - 2362	November November; 29 (11): 2363 - 2683	December December; 29 (12): 2685 - 2913