1968
February February; 58 (2): 55 - 90	March March; 58 (3): 109 - 137	April April; 58 (4): 157 - 185
May May; 58 (5): 209 - 236	June June; 58 (6): 251 - 276	July July; 58 (7): 295 - 311
August August; 58 (8): 333 - 363	September September; 58 (9): 379 - 406	October October; 58 (10): 423 - 441
November November; 58 (11): 463 - 481	December December; 58 (12): 507 - 519