HT51-1595: Communities. Classes. Races.
HT51-65: Human settlements. Communities.
HT101-395: Urban groups. The city. Urban sociology.
HT165.5-169.9: City planning.
HT170-178: Urban renewal. Urban redevelopment.
HT201-221: City population. Including children in cities, immigration.
HT231: Effect of city life.
HT251-265: Mental and moral life.
HT321-325: The city as an economic factor.
