1. ^{{cite news |first= |last= |authorlink= |coauthors= |title=Yamada Finding His Stroke at Practice -- Contestants Make Good Runs. |url=https://timesmachine.nytimes.com/timesmachine/1912/11/03/100597214.pdf |quote=The most interesting development of the past week relative to the world's championship at 18.2 balk-line billiards, to begin one week from to-morrow at the Hotel Astor, was the arrival of the Japanese expert Koji Yamada. He came from Berlin, where he resided for two years, and was highly esteemed for his professional ability. |work=New York Times |date=November 3, 1912 |accessdate=2009-08-03 | format=PDF}}
2. ^{{cite news |first= |last= |authorlink= |coauthors= |title=Yamada Defeats Former Champion Morningstar in 18.2 Tournament. |url=https://timesmachine.nytimes.com/timesmachine/1912/11/17/100381439.pdf |quote= |work=New York Times |date=November 17, 1912 |accessdate=2009-08-03 | format=PDF}}
3. ^{{cite news |author= |coauthors= |title=Hoppe To Defend Billiard Title. Champion Will Play Yamada at 18.2 Balkline at the Hotel Astor Ball Room |url=https://query.nytimes.com/gst/abstract.html?res=9D06E3D8103BE633A25756C2A9639C946296D6CF |quote=William F. Hoppe of this city and Koji Yamada of Tokio, Japan, will be contestants for the world's championship at 18.2 balkline billiards on Tuesday night in the grand ballroom of the Hotel Astor. Hoppe won the championship in the tournament last November. Last February he successfully defended it in a challenge match against George Sutton of Chicago. |work=New York Times |date=May 25, 1913 |accessdate=2010-08-04 }}