1968
January January; 2 (1): 1 - 88	February February; 2 (2): 89 - 159	March March; 2 (3): 161 - 266
April April; 2 (4): 267 - 400	May May; 2 (5): 401 - 545	June June; 2 (6): 547 - 655
July July; 2 (7): 657 - 762	August August; 2 (8): 763 - 851	September September; 2 (9): 853 - 954
October October; 2 (10): 955 - 1233	November November; 2 (11): 1235 - 1362	December December; 2 (12): 1363 - 1487