1981
January January; 31 (1): 1 - 517	February February; 31 (2): 519 - 844	March March; 31 (3): 845 - 1280
April April; 32 (1): 1 - 413	May May; 32 (2): 415 - 973	June June; 32 (3): 975 - 1309
July July; 33 (1): 1 - 329	August August; 33 (2): 331 - 645	September September; 33 (3): 647 - 961
October October; 34 (1): 1 - 314	November November; 34 (2): 315 - 639	December December; 34 (3): 641 - 1075