1999
January January; 20 (1): 1 - 177	February February; 20 (2): 181 - 358	March March; 20 (3): 361 - 537
April April; 20 (4): 541 - 847	May May; 20 (5): 849 - 1095	June June; 20 (6): 1097 - 1334
July July; 21 (1): 1 - 145	August August; 21 (2): 147 - 288	September September; 21 (3): 291 - 445
October October; 21 (4): 447 - 546	November November; 21 (5): 547 - 646	December December; 21 (6): 651 - 752