1968
January January; 58 (1): 9 - 159	February February; 58 (2): 161 - 306	March March; 58 (3): 307 - 472
April April; 58 (4): 473 - 633	May May; 59 (1): 1 - 136	June June; 59 (2): 137 - 310
July July; 59 (3): 311 - 432	August August; 59 (4): 433 - 593	September September; 60 (1): 1 - 156
October October; 60 (2): 243 - 418	November November; 60 (3): 419 - 640	December December; 60 (4): 641 - 828