Barequet, Gill (2001). «A lower bound for Heilbronn's triangle problem in d dimensions». SIAM Journal on Discrete Mathematics14 (2): 230-236. MR1856009. doi:10.1137/S0895480100365859. See the introduction, which cites the 1951 paper as "the first nontrivial upper bound" and refers to all four of Roth's papers on the Heilbronn triangle problem, calling the final one "a comprehensive survey of the history of this problem".
Vaughan, Robert C. (December 2017). «Heini Halberstam: some personal remarks». En Diamond, Harold G., ed. Heini Halberstam, 1926–2014. Bulletin of the London Mathematical Society (Wiley) 49 (6): 1127-1131. doi:10.1112/blms.12115. See page 1127: "I had attended Roth's inaugural lecture on the large sieve at Imperial College in January 1968, and as a result had started to take an interest in sieve theory."
Barequet, Gill (2001). «A lower bound for Heilbronn's triangle problem in d dimensions». SIAM Journal on Discrete Mathematics14 (2): 230-236. MR1856009. doi:10.1137/S0895480100365859. See the introduction, which cites the 1951 paper as "the first nontrivial upper bound" and refers to all four of Roth's papers on the Heilbronn triangle problem, calling the final one "a comprehensive survey of the history of this problem".