Bell telephone system technical publications.

no.481-520; no.512-529; no.521-555; no.530-553; no.556-590; no.584-602; no.591-630; no.631-670; no.638-666; no.667-699; no.671-688, 690-710; no.700-724; no.711-750; no.725-727,729-755; no.751-785; no.757-783; no.784-807 inc.; no.786-825; no.808-832; no.826-865; no.833-856 inc.; no.857-880; no.866-910; no.881-905; no.906-929; no.911-950; no.930-951; no.951-1000; no.952-974; no.974-1003; no.1001-1046; no.1004-1029; no.1030-1059; no.1047-1076; no.1060-1087; no.1077-1117; no.1088-1116; no.1117-1144; no.1118-1151; no.1145-1172; no.1152-1178; no.1173-1195; no.1179-1204; no.1196-1216 inc; no.1205-1244; no.1217-1242; no.1243-1265; no.1245-1274; no.1266-1292; no.1275-1310; no.1293-1317; no.1311-1328; no.1318-1339; no.1329-1365; no.1366-1367; B1475-1486; B1487-1499; no.1-1900 index, no.1200-2850 index; index 481-750; index 463-533; index 751-817; index 585-650; index 1205-1310