- eBookThe Radio Boys on the Mexican BorderGerald Breckenridge
- eBookThe Radio Boys Seek the Lost AtlantisGerald Breckenridge
- eBookThe Radio Boys Rescue the Lost Alaska ExpeditionGerald Breckenridge
- eBookThe Radio Boys with the Revenue GuardsGerald Breckenridge
- eBookThe Radio Boys on Secret Service DutyGerald Breckenridge
- eBookThe Radio Boys' Search for the Inca's TreasureGerald Breckenridge
- eBookThe Radio Boys on Secret Service DutyGerald Breckenridge