Wherever they are, they form a tight oligarchy.
Asimov, Isaac
Foundation 3 - Second Foundation
Whenever those states which have been acquired as stated have been accustomed to live under their own laws and in freedom, there are three courses for those who wish to hold them: the first is to ruin them, the next is to reside there in person, the third is to permit them to live under their own laws, drawing a tribute, and establishing within it an oligarchy which will keep it friendly to you.
Niccolò Machiavelli
The Prince
The city, which was owned by an oligarchy of business men, being nominally ruled by the people, a huge army of graft was necessary for the purpose of effecting the transfer of power.
Upton Sinclair
The Jungle
It embodies the heavy dignity of those Victorian financiers who ruled the generation between the pioneers and the brisk “sales-engineers” and created a somber oligarchy by gaining control of banks, mills, land, railroads, mines.
Sinclair Lewis
Babbitt
She spoke with the chiding tone she would use to a child: “Ser Waff, ask yourself why you, a ruling member of your oligarchy, came to this meeting?” His voice still firmly controlled, Waff countered: “And why did you, Mother Superior of the Bene Gesserit, come here?” She spoke mildly: “To strengthen us.” “You did not say what you would share,” he accused.
Frank Herbert
Heretics of Dune
The poorer orders (in an oligarchy) sometimes lurch about when they are slightly drunk, but generally, and especially in such gorgeous scenes, they stand or sit in constrained attitudes.
G. K. Chesterton
The Innocence of Father Brown