Question: Alex Young played later in his career for the semi-pro team taht plays in which premiership?

Context paragraphs:
Lehigh Valley Outlawz: The Lehigh Valley Outlawz were a professional indoor football team based in Bethlehem, Pennsylvania.  The team began play as a semi-pro team in the Labelle Community Football League as the "Philly Outlawz".  The team was later a charter member of the Great Lakes Indoor Football League joining the league in 2006 as an expansion team.  The Outlawz and the Reading Express were the first professional indoor football team to be based in Lehigh Valley.  The Outlawz were owned by Jim DePaul.  They played their home games at the Stabler Arena on the campus of Lehigh University in Bethlehem, Pennsylvania.

Glens Falls Greenjackets: The Glens Falls Greenjackets are a semi-professional American football team in Glens Falls, NY.  The Greenjackets compete in the Empire Football League.  They were founded in 1928 as the Hudson Falls Greenjackets, making them the second oldest semi-pro team in the United States.  The oldest American semi-pro team, Watertown Red & Black (1896), also competes in the EFL.  Home games are played at East Field in Glens Falls, NY.  Preseason games are played at East Field and Putt LaMay Memorial Field (Glens Falls High School).

St. Petersburg Saints: The St. Petersburg Saints were a minor league baseball team that operated out of St. Petersburg, Florida.  The team began as a semi-pro team and as early as October 1908, the semi-pro Saints played the Cincinnati Reds in a post-season exhibition game.  By 1914, the Saints were receiving regular coverage in the local press.  They played in the Florida State League from 1920-1928 and then folded operations.  A second team, also called the St.Petersburg Saints played in the Florida International League from 1947-1954 and the Florida State League from 1955-1965.  The team won four championships and were owned by R. Vernon and Irene C. Eckert from 1951-1954.

Akron Pros: The Akron Pros were a professional football team that played in Akron, Ohio, from 1908 to 1926.  The team originated in 1908 as a semi-pro team named the Akron Indians, but later became Akron Pros in 1920 as the team set out to become a charter member of the American Professional Football Association (later renamed the National Football League (NFL) in 1922).  Fritz Pollard, the first black head coach in the NFL, co-coached the Akron Pros in 1921.  Paul Robeson played for the team in 1921 as well.  He was among the earliest stars of professional football, before football became segregated from 1934 to 1946.  In 1926, the name was changed back to the Akron Indians, after the earlier semi-pro team.  Due to financial problems, the team suspended operations in 1927 and surrendered its franchise the following year.

Glentoran F.C.: Glentoran Football Club is a semi-professional football club that plays in the NIFL Premiership.  The club was founded in 1882 and plays its home games at the Oval in east Belfast.  Club colours are red, green and black.  Linfield and Glentoran are nicknamed Belfast's "Big Two", as they have traditionally dominated local football in Northern Ireland since the demise of Belfast Celtic.  The two play a league match on Boxing Day each year, which regularly attracts the largest attendance of the Irish League season.

Bedford Blues: Bedford Blues are a rugby union club in the town of Bedford, England, currently playing in The RFU Championship.  Bedford is one of the largest towns in England without a league football club, and one of the few towns in England where the rugby club is better supported than the football team.  The Blues are a semi-pro team, with a mix of experienced and young players.  The Blues are coached by Mike Rayer.  Rayer, an ex-player of the club and Cardiff, has introduced a free-flowing style which saw Bedford rise to 2nd in the league in 2006, only held back by the dominance of Harlequins, who had been demoted from the Premiership the year before.

1926 Rock Island Independents season: The 1926 Rock Island Independents season was their only season in the first American Football League, after jumping to the upstart league from the National Football League.  The team finished 2–6 in league play and 2–7–2 overall, earning them seventh place in the league.  The Independents struggled to bring in 5000 fans to its home games and later became a traveling team after having poor attendance in its first three games.  The AFL folded after the 1926 and the Independents did not rejoin the NFL.  They instead played as a minor, semi-pro team in 1927, then folded.

Alex Young (footballer, born 1937): Alexander Young (3 February 1937 – 27 February 2017) was a Scottish international footballer.  He played as a creative forward for Heart of Midlothian and Everton.  He won league championship and cup titles with both clubs where he was also a regular goal scorer.  Young later played for Glentoran and Stockport County.  Internationally he played for the Scottish League and the Scotland national football team.  In football folklore he has become known as 'The Golden Vision'.

Pittsburgh Yellow Jackets: Pittsburgh Yellow Jackets was the name of two separate ice hockey teams based in Pittsburgh, Pennsylvania.  The original team played from 1915–1925.  They evolved from being an amateur to a semi-pro team and are one of the earliest sports organizations in Pittsburgh, Pennsylvania.  The Yellow Jackets played primarily in the United States Amateur Hockey Association (USAHA).  After winning the USAHA Championship in 1924 and 1925, the Yellow Jackets were sold to attorney James Callahan and soon became the Pittsburgh Pirates of the National Hockey League.  However, after the demise of the Pirates in 1930, a second club (founded by the owner of the original club), debuted in the IHL as a professional entity, before reverting to an amateur club in 1934.  The team would finish its run in the EAHL, before finally folding in 1937.

Leon Gajecki: Leon J. Gajecki (December 10, 1917 - November 2, 2000) was an American football player.  He played college football for the Penn State Nittany Lions football team and was selected by both the Newspaper Enterprise Association and "Liberty" magazine as a first-team center on the 1940 College Football All-America Team.  After graduating in 1940, Gajecki was drafted by the Pittsburgh Steelers.  He then played for the Jersey City Giants, a semi-pro team, in 1947 and 1948.  Later Gajecki worked for more than 30 years for Exxon.  He was inducted into the Cambria County Sports Hall of Fame in 1971.  He died in 2000 at age 82.

Supporting paragraphs: Alex Young (footballer, born 1937) Glentoran F.C.
Answer: NIFL