Question: Which other retailer did Sam Walton establish besides the world's largest retailer Walmart?

Context paragraphs:
Walmart: Wal-Mart Stores, Inc. ( ), doing business as Walmart, is an American multinational retailing corporation that operates as a chain of hypermarkets, discount department stores, and grocery stores. Headquartered in Bentonville, Arkansas, the company was founded by Sam Walton in 1962 and incorporated on October 31, 1969.  s of 31, 2017 , Walmart has 11,695 stores and clubs in 28countries, under a total of 63banners.  The company operates under the name Walmart in the United States and Canada.  It operates as Walmart de México y Centroamérica in Mexico and Central America, as Asda in the United Kingdom, as the Seiyu Group in Japan, and as Best Price in India.  It has wholly owned operations in Argentina, Chile, Brazil, and Canada.  It also owns and operates the Sam's Club retail warehouses.

Wake Up Wal-Mart: Wake Up Wal-Mart was a campaign founded by United Food and Commercial Workers Union.  It is based in Washington, D.C. and is often critical of the business practices of Walmart, the world's largest retailer, and the largest private employer in the United States.  The group claims Wal-Mart is currently offering its employees substandard wages and health care benefits, and has called on the retailer to improve both.  Wake Up Wal-Mart was founded April 5, 2005 and maintains the web site WakeupWalMart.com, the centerpiece of the organization.  The organization is now defunct.  Its website is no longer active and the url wakeupwalmart.com now redirects to another UFCW-funded group, Making Change At Walmart.

Walton family: The Walton family is an American family whose collective fortune makes them among the richest families in the world.  The majority of their wealth derives from the heritage of Bud and Sam Walton, who were the co-founders of the world's largest retailer, Walmart.  The three most prominent living members (Jim, Rob and Alice) have consistently been in the top ten of the "Forbes" 400 since 2001, as were John ( 2005) and Helen (d. 2007) prior to their deaths.  Christy Walton took her husband John's place after his death.

Costco: Costco Wholesale Corporation trading as Costco, is the largest American membership-only warehouse club.  As of 2015, Costco was the second largest retailer in the world after Walmart, and as of 2016, Costco was the world's largest retailer of choice and prime beef, organic foods, rotisserie chicken, and wine.

Audrey J. Walton Stadium (Columbia, Missouri): Audrey J. Walton Stadium on the campus of the University of Missouri is the home of the Missouri Tigers track and field teams and the Missouri Relays track and field meet.  Audrey J. Walton, the namesake of the Stadium, was married to Sam Walton's brother, Bud Walton.  Sam Walton is the founder of Wal-Mart and an alumnus of the University.  The stadium has a seating capacity of 2,500 and is also the home of the men's and women's soccer teams at the University of Missouri.

S. Robson Walton: Samuel Robson "Rob" Walton (born October 28, 1944) is an American businessman and is the eldest son of Helen Walton and Sam Walton, founder of Walmart, the world's largest retailer.  He served as Chairman of Walmart from 1992 to 2015.  In October 2012, Walton was listed as the 11th richest person in the world.

Sam Walton: Samuel Moore Walton (March 29, 1918 – April 5, 1992) was an American businessman and entrepreneur best known for founding the retailers Walmart and Sam's Club.

Jim Walton: James Carr Walton (born June 7, 1948) is the youngest son of Sam Walton, the founder of the world's largest retailer, Walmart.  On the 2016 Forbes list of world billionaires, Jim Walton was ranked as #15 with a net worth of $33.6 billion.

Greg Penner: Gregory B. "Greg" Penner (born 18 December 1969) is an American businessman and venture capitalist.  Penner was named the chairman of Walmart on June 5, 2015.  He is the son-in-law of S. Robson Walton and the grandson-in-law of Sam Walton, the founder of Walmart.

Sam's Club: Sam's West, Inc. (doing business as Sam's Club) is an American chain of membership-only retail warehouse clubs owned and operated by Walmart, founded in 1983 and named after Walmart founder Sam Walton.  s of 2012 , Sam's Club chain serves 47 million U.S. (including Puerto Rico) members and is the 8th largest U.S. retailer.  s of 31, 2008 , Sam's Club ranks second in sales volume among warehouse clubs with $56.828 billion in sales (in fiscal year 2016) behind Costco.

Supporting paragraphs: S. Robson Walton Sam Walton
Answer: Sam's Club