@article {2850,
	title = {Integrals of Production Sets with Restricted Substitution},
	journal = {Journal of Mathematical Economics},
	volume = {9},
	year = {1982},
	pages = {71-82},
	abstract = {It is well known that the set of all zonoids (integrals of line segments) in R" (n\&gt;2) is a closed\&nbsp;and nowhere defise subset in the space of all compact, convex and centrally symmetric subsets of\&nbsp;R". We generalize this result to sets which are the integral of k-dimensional convex sets, k \&lt;n.},
	author = {Abraham Neyman and Werner Hildenbrand}
}
