Becky M. Nicolaides, My Blue Heaven: Life and Politics in the Working-Class Suburbs of Los Angeles, 1920-1965, Photographs by Robbert Flick, The University of Chicago Press: Chicago, 2002, 1940
"Using the Sixteenth Census of the United States, 1940, gives the percentage of residents with working-class jobs in Santa Monica, whose population was then 53,500, as 53.2%."