Question: Hardy Brown is one of only two men to play in the NFL, AAFC and AFL, but which Oklahoma college did he play football for?

Context paragraphs:
List of Cleveland Browns seasons: The Cleveland Browns were a charter member club of the All-America Football Conference (AAFC) when the league was founded in 1946.  From 1946 to 1949, the Browns won each of the league's four championships.  The National Football League (NFL) does not recognize the Browns' AAFC championships; however, the Pro Football Hall of Fame "does" recognize the team's championships, which is reflected in this list.  When the AAFC folded in 1949, the Browns were absorbed into the NFL in .  The Browns went on to win three NFL championships, nearly dominating the NFL in the 1950s, and won one more NFL championship in 1964.  The team has yet to appear in a Super Bowl, however.  Overall, the team has won eight championships: four in the AAFC, and four in the NFL.

All-America Football Conference: The All-America Football Conference (AAFC) was a professional American football league that challenged the established National Football League (NFL) from 1946 to 1949.  One of the NFL's most formidable challengers, the AAFC attracted many of the nation's best players, and introduced many lasting innovations to the game.  However, the AAFC was ultimately unable to sustain itself in competition with the NFL.  Three of its teams were admitted to the NFL: the San Francisco 49ers, the Cleveland Browns and the Baltimore Colts (not directly antecedent to the later second Colts team that would play in Baltimore in the NFL from 1953 through 1983, now the Indianapolis Colts).

Paul Salata: Paul Thomas Salata (born on October 17, 1926) is a former professional American football wide receiver in the National Football League (NFL) and the All-America Football Conference (AAFC).  He was born to a Serbian-born father and second generation Serbian-American mother.  After his college football days at USC, Salata played for the AAFC/NFL's San Francisco 49ers (1949–1950) and the AAFC's Baltimore Colts (1950).  After the Colts franchise folded in 1950 he was declared draft-eligible and was subsequently drafted in the tenth round of the 1951 NFL Draft by the Pittsburgh Steelers.  He scored the 49ers final touchdown in the All-American Football Conference, as well as the team's first TD in NFL.  He also played three final seasons in Canada; 1952 with the Calgary Stampeders, where he was an all-star, and 1953 with the Ottawa Rough Riders.

Chubby Grigg: Forrest Porter "Chubby" Grigg, Jr. (January 10, 1926 – October 10, 1983) was an American football tackle who played seven seasons in the All-America Football Conference (AAFC) and National Football League (NFL) in the 1940s and 1950s.  Grigg grew up in Texas and attended the University of Tulsa in Oklahoma.  After graduating from college, he joined the AAFC's Buffalo Bisons, where he played for a year.  Grigg was then sent to the Chicago Rockets in 1947, but stayed only one season before joining the Cleveland Browns in 1948.  The Browns won all of their games and the AAFC championship that season.  Cleveland again won the AAFC championship in 1949 before the league dissolved and the Browns were absorbed by the more established NFL.  Grigg continued to play for the Browns in 1950 and 1951.  The team won the NFL championship in 1950, and reached the title game but lost it the following year.  Grigg spent a final season with the Dallas Texans before retiring from football.

Bob Adams (American football): Robert Bruce "Bob" Adams (born August 15, 1946) is a former professional American football tight end in the National Football League (NFL) and a spokesperson for the Church of Scientology International.  He attended El Camino High School during the 1960s, and was encouraged by a coach at the College of San Mateo to play football.  He played for a single season at the college, during 1966, while participating in other sports at the school including track-and-field and basketball.  A former coach of the College of San Mateo, Doug Scovil, recruited Adams to the College of the Pacific, where he received a full scholarship to play football there.  By 1968, he was captain of the team's offense at the school.

University of Tulsa: The University of Tulsa (TU) is a private research university located in Tulsa, Oklahoma, United States.  The university is renowned for its programs in law, English, computer science, natural sciences, psychology, and engineering.  Its faculty includes prominent scholars, scientists, and writers, including Russian dissident poet Yevgeny Yevtushenko, political scientist Robert Donaldson and others.  The university has a historic affiliation with the Presbyterian Church and the campus's architectural style is predominantly Collegiate Gothic.

Lou Rymkus: Louis Joseph "the Battler" Rymkus (November 6, 1919 – October 31, 1998) was an American football player and coach in the All-America Football Conference (AAFC), National Football League (NFL) and American Football League (AFL).  Playing as a tackle for the Cleveland Browns in the AAFC and NFL in the late 1940s and early 1950s, Rymkus provided pass protection for quarterback Otto Graham as the team won five league championships.  Following his playing career, Rymkus took a number of assistant coaching jobs before serving as the first head coach of the AFL's Houston Oilers in 1960.  The team won the league's first championship, but Rymkus was fired by Oilers owner Bud Adams after a slow start in 1961.

Hardy Brown: Hardy Brown (May 8, 1924 – November 8, 1991) was an American football linebacker in the National Football League (NFL), All-America Football Conference (AAFC), and the American Football League (AFL).  He played college football at the University of Tulsa and then professionally for the San Francisco 49ers, Washington Redskins, and the Denver Broncos.  He was one of only two men who played in the All-America Football Conference, the National Football League, and the American Football League (the other was Ben Agajanian).

Otto Graham: Otto Everett Graham Jr. (December 6, 1921 – December 17, 2003) was an American football quarterback who played for the Cleveland Browns in the All-America Football Conference (AAFC) and National Football League (NFL).  Graham is regarded by critics as one of the most dominant players of his era, having taken the Browns to league championship games every year between 1946 and 1955, winning seven of them.  With Graham at quarterback, the Browns posted a record of 114 wins, 20 losses, and four ties, including a 9–3 win–loss record in the playoffs.  While most of Graham's statistical records have been surpassed in the modern era, he still holds the NFL record for career average yards gained per pass attempt, with 8.98.  He also holds the record for the highest career winning percentage for an NFL starting quarterback, at 0.814.  Long-time New York Yankees owner George Steinbrenner, a friend of Graham's, once called him "as great of a quarterback as there ever was."  He is also known for being one of only two people (the other being Gene Conley) to win championships in two of the four major North American sports—1946 NBL (became NBA) and AAFC championship, plus three more AAFC and three NFL championships.

Al Coppage: Alton Minor Coppage (February 8, 1916 – January 9, 1992) was a professional American football end who played five seasons in the National Football League (NFL) and All-America Football Conference (AAFC), mostly for the Chicago Cardinals.  Coppage grew up in Oklahoma and attended the University of Oklahoma, where he was part of a 1938 football team that won the school's first Big Six Conference championship.  He was drafted by the NFL's Cardinals in 1940 and played in Chicago for three seasons before leaving to serve in World War II.  He signed with the Cleveland Browns in the AAFC after his discharge from the military and played one season for the team, moving to the Buffalo Bills in 1947.  After leaving football, Coppage settled in Oklahoma and worked in lumber and banking.  He died in 1992.

Supporting paragraphs: Hardy Brown University of Tulsa
Answer: University of Tulsa