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)
Great Eastern Bus Co. - existed in 1930's, also served Allentown.
Lebanon Auto Bus Co. - served Lebanon, Cornwall, Manheim, Lancaster, Marietta, Columbia, Indiantown Gap. Was listed in 1942 Russell's Guide.
Penn Highway Transit Co. - served Long Park, Landisville, Salunga, Mount Joy, Florin, Hershey, Witmer Heights, Smoketown, Bird In Hand, Weavertown, Intercourse, Spring Garden, White Horse.
Lancaster-Bainbridge Bus Co. - served Lancaster, Bainbridge MD.