@article{74e65189649848b2be2ce48bd6b312ad,
title = "Nine kinds of quasiconcavity and concavity",
author = "Diewert, {W. E.} and M. Avriel and I. Zang",
note = "Funding Information: Our criterion for quasiconcavity in the twice continuously differentiable case can be derived from a criterion involving only local properties of the function. It turns out to be possible to characterize all seven varieties of * This research was supported by a Canada Council grant. We are indebted to C. Blackorby and M. Truchon for helpful comments. 397",
year = "1981",
month = dec,
doi = "10.1016/0022-0531(81)90039-9",
language = "אנגלית",
volume = "25",
pages = "397--420",
journal = "Journal of Economic Theory",
issn = "0022-0531",
publisher = "Academic Press Inc.",
number = "3",
}