1968
January January; 52 (1): 1 - 244	February February; 52 (2): 251 - 502	March March; 52 (3): 503 - 723
April April; 52 (4): 725 - 933	May May; 52 (5): 935 - 1115	June June; 52 (6): 1117 - 1277
July July; 53 (1): 1 - 187	August August; 53 (2): 189 - 329	September September; 53 (3): 355 - 461
October October; 53 (4): 501 - 665	November November; 53 (5): 667 - 881	December December; 53 (6): 883 - 1123