1970
January January; 19 (1): 1 - 206	February February; 19 (2): 207 - 399	March March; 19 (3): 401 - 555
April April; 19 (4): 557 - 705	May May; 19 (5): 707 - 881	June June; 19 (6): 883 - 1025
July July; 20 (1): 1 - 169	August August; 20 (2): 171 - 291	September September; 20 (3): 293 - 530
October October; 20 (4): 531 - 654.1	November November; 20 (5): 657 - 853.1	December December; 20 (6): 855 - 998