Official publications released by the U.S. Census Bureau have a report number and often list the lead author(s).
1940 Census of Population and Housing: Families
Families classified by size, number of children 21 years old, number of persons in the labor force, etc. Heads of families shown by sex, marital status, etc.
1940 Census of Population: Education
A series of reports presenting detailed sample statistics on education cross-classified with various other characteristics.
1940 Census of Population: Families
These reports cover types of families, size of family and age of head, employment status, and family wage or salary income in 1939.
1940 Census of Population: The Labor Force (Sample Statistics)
A series based on tabulations of samples of the 1940 census returns and covers general, occupational and industrial characteristics of the labor force.