--subdivision Health and hygiene under occupational groups, e.g. Printers--Health and hygiene; also subdivision Employees--Health and hygiene under types of industries, e.g. Construction industry--Employees--Health and hygiene; and subdivision Health aspects under types of industries, structures, and processes, e.g. Construction industry--Health aspects; Welding--Health aspects
--subdivision Health and hygiene under ethnic groups and classes of persons; and subdivision Health aspects under topics and individual wars, e.g. Recreation areas--Health aspects; World War, 1939-1945--Health aspects
