Census of 1890: Transportation in the United States.
Census of 1890, Bulletin: Transportation Business in the United
States (Part II), Transportation by Express Companies (1894).
Express business in the United States (1907).
CHANDLER, WILLIAM H.--The Express Service and Rates (1914).
CONGRESSIONAL RECORD, 1911 AND 1912--Speeches, bills, etc., concerning
the parcel-post and express service.