Williams Companies

Lippincott Williams & Wilkins. 2006: 385. ISBN 978-1-58255-939-1.  F. Gary Cunningham, 2005. Williams Obstetrics, 22nd Edition, McGraw-Hill Companies.

Instead of honoring the notion of share-and-share alike, Reid had inserted a way for companies to compel programmers to pay for information access. 

Internal Medicine 互联网档案馆的存檔，存档日期2012-08-04. 16th Edition, The McGraw-Hill Companies, ISBN 0-07-140235-7Cecil Textbook of Medicine 互联网档案馆的存檔，存档日期2010-06-16

11, 2011 [2022-12-05]. （原始内容存档于2022-11-29）.  Duggan, Dennis. Two More Companies Leave Thorny Computer Market. The Washington Post. July 8, 1965.  Quoted

（原始内容存档于2019年1月16日）.  Williams, Matthew. FedEx delivers upgrade from Europa League to Champions League sponsor. SportBusiness (SBG Companies Limited). [5 May