Key points are not available for this paper at this time.
Selwyn D. Collins, W. H. Frost, Mary Gover, Edgar Sydenstricker, Mortality from Influenza and Pneumonia in 50 Large Cities of the United States, 1910-1929, Public Health Reports (1896-1970), Vol. 45, No. 39 (Sep. 26, 1930), pp. 2277-2328
Collins et al. (Wed,) studied this question.