| Year | 1920 |
| Date | 12-Aug |
| Volume | 43 |
| Issue | 1,007 |
| Page | 126 |
| Category | Electronic |
| Part | |
| Title | Duplex Wireless Telephony: Some Experiments on its Application to Aircraft |
| Author | Captain P.P.Eckersley |
| Notes | 3. - True Duplex Wireless Telephony Systems. 4. - Partial Duplex. 5. - Subsidiary Problems. Conclusion |