scientific article published in 1955

scientific article published in June 1994

scientific article published in 1968

scientific article published in March 1956

scientific article published in September 1952

scientific article published in March 1967

scientific article published in 1954

scientific article published in 1971

scholarly article published in American Mathematical Monthly

article

scientific article published in 1980

scientific article published in November 1969

scientific article published in 1962

scientific article published in April 1964

doctoral dissertation by Paul Cohn

scientific article published in September 1973

scientific article (publication date: November 1989)

scientific article published in August 1976

article published in 1963

scientific article published in 1970

scientific article published in March 1980

scientific article published in 1985

scientific article published in 1981

scientific article published in 1954

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scientific article published in 1954

scientific article published in 1953

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scientific article published in July 1979

scientific article published in 1961

scientific article published in December 1959

scientific article published in October 1960

scientific article published in March 1968

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scientific article published in May 1982

scientific article published in December 1966

scientific article published in January 1975

scientific article published in March 1974

scientific article published in 1961

scientific article published in September 1990

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scientific article published in April 1987

scientific article published in March 1979

scientific article published in July 2003

scientific article published in September 1966

scientific article published in October 1964

scientific article published in 1969

scientific article published in 2002

scientific article published in September 1971

scientific article published in November 1973

scientific article published in June 1973

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