1991
January January; 5 (1): 1 - 158	February February; 5 (2): 159 - 310	March March; 5 (3): 311 - 460
April April; 5 (4): 461 - 613	May May; 5 (5): 615 - 740	June June; 5 (6): 741 - 879
July July; 5 (7): 881 - 1035	August August; 5 (8): 1037 - 1201	September September; 5 (9): 1203 - 1360
October October; 5 (10): 1361 - 1570	November November; 5 (11): 1571 - 1772	December December; 5 (12): 1773 - 2061