1968
January January; 28 (1): 1 - 130	February February; 28 (2): 137 - 316	March March; 28 (3): 325 - 428
April April; 28 (4): 433 - 585	May May; 28 (5): 591 - 745	June June; 28 (6): 749 - 930
July July; 28 (7): 937 - 1088	August August; 28 (8): 1105 - 1230	September September; 28 (9): 1245 - 1393
October October; 28 (10): 1401 - 1517	November November; 28 (11): 1525 - 1678	December December; 28 (12): 1683 - 1847