James Bell Cooper,
"Characterizing an area condition associated with minimizing systems, in Economic Theory, Dynamics and Markets"
, in T. Nageshi, R.V. Ramachandran and K. Mino: Essays in honour of Ryuzo Sato, Kluwer, Norwell, Mass., 2006
Original Titel:
Characterizing an area condition associated with minimizing systems, in Economic Theory, Dynamics and Markets