1929 Indianapolis 500 Practice. In: The Indianapolis News. Indianapolis, Indiana 9. Mai 1929, S.30 (newspapers.com [abgerufen am 21. März 2021]).
nytimes.com
RAY KEECH KILLED AS 4 RACERS CRASH; Former Holder of World Speed Record Dies Leading Contest in Altoona (Pa:) Bowl. CLIFF WOODBURY IS HURT Accident Follows Striking of Hole in Track by One Car, Pitching It Into Rail. In: The New York Times. 16. Juni 1929, ISSN0362-4331 (nytimes.com [abgerufen am 20. März 2021]).
RAY KEECH KILLED AS 4 RACERS CRASH; Former Holder of World Speed Record Dies Leading Contest in Altoona (Pa:) Bowl. CLIFF WOODBURY IS HURT Accident Follows Striking of Hole in Track by One Car, Pitching It Into Rail. In: The New York Times. 16. Juni 1929, ISSN0362-4331 (nytimes.com [abgerufen am 20. März 2021]).