Additional bus companies, listed as existing during additional years or decades, are mentioned in old City Directories, and in the WPA American Guide Series of state guidebooks.
For some of the earliest bus companies, listed in early reports of the Ohio Public Utilities Commission, a first year of operations is listed.
Suburban and interurban bus companies listed in the Russell's Official National Motor Coach Guide, which was primarily a resource for intercity bus lines.
Croswell Transportation Co. (began operations in 1929, to Williamsburg and Portsmouth, until 1960)
King Brothers Lines (began operations in 1922, to Dayton, Portsmouth, New Richmond, Franklin, until 1948. Absorbed into Ohio Bus Line.)
Dayton Lebanon & Cincinnati Bus Co. - existed in 1930's to 1940's.
Lockland Bus Co. - served Lockland, Woodlawn, Lincoln Heights.
Price Hill Coach Lines - connected Cincinnati with Cheviot.
Beel Transportation - served Lebanon, South Lebanon, Kings Mills, Mason.