| Call Number | Subject |
|---|---|
| HE 8701 - 9685 | Telephone industry |
| HE 9713 - 9756 | Cell phone services industry. Wireless telephone industry Artificial satellite telecommunications -- Signaling -- Messenger service |
See also HD9697.T45+ Telephone supplies industry; TK6001+ Technology
| Call Number | Subject |
|---|---|
| HE 8721 | Directories & buyers' guides (General) |
| HE 8731 | General works |
| HE 8761-8784 | Management |
| HE 8788-8789 | Call centers |
| - HE 8789.A-Z | - By region or country, A-Z |
| - - HE 8789.I4 | - - India |
| - - HE 8789.P6 | - - Philippines |
| - - HE 8789.U6 | - - United States |
| HE 8800-9680.7 | By region or country |
| - HE 8801-8846 | - United States |
| - - HE 8811 | - - Directories |
| - - HE 8815 | - - General works |
| - - HE 8819 | - - Government policy |
| - - HE 8846.A-Z | - - By company, A-Z |
| - - - HE 8846.A54-.A55 | - - - American Telephone & Telegraph (AT&T) |
| - HE 8861-9680.7 | - Other regions or countries |
| - - HE 8861-8870 | - - Canada |
| - - HE 8870.5-9130 | - - Latin America |
| - - HE 9131-9390.8 | - - Europe |
| - - HE 9511-9577 | - - Africa |
| Call Number | Subject |
|---|---|
| HE 9713-9715 | Cell phone services industry. Wireless telephone industry |
| - HE 9715.A-Z | - By region or country, A-Z |
| - - HE 9715.A35 | - - Africa |
| - - HE 9715.D48 | - - Developing countries |
| - - HE 9715.U6 | - - United States |
| HE 9719-9721 | Artificial satellite telecommunications See also TK5104+ Engineering |
| HE 9723-9737 | Signaling See also VK381+ Marine signaling |
| HE 9751-9756 | Messenger service Including bicycle messengers |