Columbia subject headings:
Informal sector (Economics)--England--London.
Informal sector (Economics)--Mexico--Mexico City.
Street vendors--England--London.
Street vendors--Mexico--Mexico City.
Harvard subject headings:
Informal sector (Economics)--England--London.
Informal sector (Economics)--Mexico--Mexico City.
Street vendors--England--London.
Street vendors--Mexico--Mexico City.
Princeton subject headings:
Informal sector (Economics)--England--London.
Informal sector (Economics)--Mexico--Mexico City.
Markets--England--London.
Markets--Mexico--Mexico City.
Street vendors--England--London.
Street vendors--Mexico--Mexico City.