George Bergman, "A number system with an irrational base," Mathematics Magazine, Vol. 31, No. 2, Nov.-Dec. 1957, pp. 98-110.
George Mark Bergman is an American mathematician who was born on July 22, 1943 in Brooklyn, New York. He was 14 years old at the time of publication. The paper is referenced in Knuth's TAOCP. According to the journal's publisher, the Mathematical Association of America (bolding mine):
Mathematics Magazine is an Open Select, international, peer-reviewed journal publishing high-quality, lively, readable, and appealing exposition on a wide range of mathematical topics, including original mathematics, historical content, and connections among mathematics and other disciplines.
G. L. Alexanderson (ed.), Harmony of the World: 75 Years of Mathematics Magazine, Mathematical Association of America 2007, is a collection of selected papers from the journal's history. Bergman's paper appears on pp. 99-106. According to the editor's note:
This article was written by the author when he was a 12-year old student at Junior High School 246 in Brooklyn, New York. Here he explores using the golden mean, which he calls τ, more commonly now called ϕ, as the base of a number system. Bergman later went on to get a PhD at Harvard under the direction of John Tate and has had a distinguished career as a mathematician at the University of California, Berkeley.
Pr$\infty$fWiki lists the publication in their article stub on Bergman.