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- Secret service — United States -- Juvenile fiction
Secret service — United States -- Juvenile fiction — Audiobooks
Eagles of the Sky; Or, With Jack Ralston Along the Air Lanes
by Ambrose Newcomb
The Sky Pilot's Great Chase; Or, Jack Ralston's Dead Stick Landing
by Ambrose Newcomb
Wings Over the Rockies; Or, Jack Ralston's New Cloud Chaser
by Ambrose Newcomb
The Sky Detectives; Or, How Jack Ralston Got His Man
by Ambrose Newcomb
Trackers of the Fog Pack; Or, Jack Ralston Flying Blind
by Ambrose Newcomb
The Young Wireless Operator—With the U. S. Secret Service
by Lewis E. (Lewis Edwin) Theiss
Flying the Coast Skyways; Or, Jack Ralston's Swift Patrol
by Ambrose Newcomb