Friedrich A. Sorge's Labor Movement in the United States: A History of the American Working Class from Colonial Times to 1890 Philip S. Foner; Brewster Chamberlin; Angela Chamberlin; Brewster Chamberlin.
Greenwood Press, 1977
Postal Proposal Makes Room for 'Business Class.' (UnitedStates Postal Service; Mail Classification; Postal Rates) (Update) Miller, Paul.
Folio: the Magazine for Magazine Management, Vol. 20, No. 5, May 1, 1991
Skies Still Looking Stormy for Unionized Airline Workers but United Airlines Is Taking Steps to Reconcile with Employees James L. Tyson, writer of The Christian Science Monitor.
The Christian Science Monitor, December 6, 1993