Additional bus companies, listed as existing during 1930's, are mentioned in the WPA American Guide Series of state guidebooks.
Suburban and interurban bus companies listed in the Russell's Official National Motor Coach Guide, which was primarily a resource for intercity bus lines.
Reading Transportation Co./Reading Trailways (served Philadelphia and Allentown and Reading and Shamokin and Harrisburg and Lancaster)
Allentown & Reading Transit Co. - served Allentown, Reading, Fleetwood, Kutztown, also existed in 1930's.
Alma Lines - existed in 1930's.
Doylestown & Easton Motor Coach - existed in 1930's, also served Philadelphia.
Golden Arrow Bus Lines - existed in 1930's.
Great Eastern Bus Co. - existed in 1930's, also served Lancaster.
Klipple Bus Lines - served Bethlehem, Bath, Nazareth, Northampton, Easton.
Perikomen Valley Bus Co. - served Allentown, Boyertown, Red Hill, Pennsburg, also existed in 1930's.
Riegelsville-Bethlehem Bus Service - served Riegelsville, Bethlehem, Springtown, Leithsville.
Waer Lines - existed in 1930's, served Easton.
Yellow Cab Co. - served Bethlehem, Coopersburg.
B. C. Daniels Bus & Taxi Service - served Palmerton, Slatington, Bowmanstown.